Method and device for receiving CTS frame in idle channel excluding busy channel by transmitting MU-RTS TXS trigger frame using bandwidth signaling ta in wireless LAN system

Abstract

Proposed are a method and device for receiving a CTS frame in an IDLE channel excluding a BUSY channel by transmitting an MU-RTS TXS trigger frame using a bandwidth signaling TA in a wireless LAN system. Specifically, a first AP transmits a MU-RTS TXS trigger frame to a second AP and receives a CTS frame from the second AP. The MU-RTS TXS trigger frame includes first and second parameters. The first parameter is related to a transmission bandwidth of the MU-RTS TXS trigger frame. The second parameter is related to a dynamic bandwidth of the CTS frame. On the basis that a portion of channels in the transmission bandwidth is set as BUSY and the second parameter is set as dynamic, the dynamic bandwidth of the CTS frame is configured by using the remaining channels, excluding the portion of channels in the transmission bandwidth.

Description

Method and apparatus for receiving a CTS frame on an IDLE channel excluding a BUSY channel by transmitting a MU-RTS TXS trigger frame using a BANDWIDTH SIGNALING TA in a wireless LAN system.

[0001] The present specification relates to a technique for receiving a CTS frame in an IDLE channel excluding a BUSY channel by transmitting a MU-RTS TXS trigger frame using a bandwidth signaling TA in a wireless LAN system, and more specifically, to a method and apparatus for adjusting the operating bandwidth of a CTS frame to the remaining IDLE channel by setting DYN_BANDWIDTH_IN_NON_HT to dynamic even if some of the channels indicated in the RU allocation field of the MU-RTS TXS trigger frame are BUSY.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability when transmitting signals to STAs, and to this end, various technologies are being considered to support high throughput, low latency, and extended range. For example, multiple APs can cooperate to perform a TXOP sharing procedure.

[0003] The present specification proposes a method and apparatus for receiving CTS frames in an IDLE channel excluding a BUSY channel by transmitting a MU-RTS TXS trigger frame using a bandwidth signaling TA in a wireless LAN system.

[0004] One example of the present specification proposes a method for receiving CTS frames in IDLE channels excluding BUSY channels by transmitting MU-RTS TXS trigger frames using bandwidth signaling TA.

[0005] This embodiment can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0006] This embodiment may be performed at a first AP. The first AP may be a MAPC requesting AP that initiates MAPC negotiation with the second AP regarding at least one MAPC technique. The second AP may be a MAPC responding AP that responds to the MAPC requesting AP. Additionally, the first and second APs may be established as a coordinating AP or a coordinated AP through the MAPC negotiation.

[0007] The present embodiment proposes a method for performing Co-TDMA operation by transmitting a MU-RTS TXS trigger frame using bandwidth signaling TA and receiving a CTS frame on an IDLE channel excluding a BUSY channel. Specifically, the present embodiment proposes a method for adjusting the operating bandwidth of the CTS frame to the remaining IDLE channel by setting DYN_BANDWIDTH_IN_NON_HT to dynamic, even if some of the channels indicated in the RU allocation field of the MU-RTS TXS trigger frame are BUSY. This has the effect of increasing the success rate of switching between the MU-RTS TXS trigger frame and the CTS frame, thereby reducing failures in Co-TDMA operation and increasing media utilization.

[0008] The first AP (access point) sends a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to the second AP.

[0009] The first AP receives a CTS (Clear To Send) frame from the second AP.

[0010] The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP. The second AP is a coordinated AP that participates in the MAPC transmission.

[0011] The above MAPC transmission may be a Co-TDMA (Coordinated Time Division Multiple Access) transmission or procedure. The above Co-TDMA transmission or procedure may be a mechanism in which one AP (Co-TDMA coordinating AP) sequentially allocates a portion of the TXOPs it has acquired to one or more other APs (Co-TDMA coordinated APs) on a time-by-time basis, so that each AP can independently perform PPDU exchanges during the corresponding time. In this case, the first AP may be a Co-TDMA coordinating AP, and the second AP may be a Co-TDMA coordinated AP.

[0012] The above Co-TDMA transmission or procedure may be performed in a polling phase, a TXOP allocation phase, and a TXOP return phase.

[0013] A TXOP for MAPC transmission may be allocated to the second AP based on the above MU-RTS TXS trigger frame. That is, the above MU-RTS TXS trigger frame may be used for Co-TDMA-based TXOP sharing in the TXOP allocation step. At this time, the TXOP allocated to the second AP may be a part of the TXOP acquired by the first AP.

[0014] The above MU-RTS TXS trigger frame includes a first and a second parameter. The first parameter is related to the transmission bandwidth of the MU-RTS TXS trigger frame. The second parameter is related to the dynamic bandwidth of the CTS frame.

[0015] Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the above channels from the above transmission bandwidth.

[0016] According to an embodiment proposed in this specification, by using a MU-RTS TXS trigger frame including a bandwidth signaling TA, the bandwidth for receiving CTS frames from APs participating in Co-TDMA operation can be flexibly controlled at the physical layer level. In particular, even when some of the channels indicated by the RU allocation field of the MU-RTS TXS trigger frame are in a BUSY state due to interference, collision, or external BSS, by setting the DYN_BANDWIDTH_IN_NON_HT parameter to dynamic, the Co-TDMA coordinated AP can automatically exclude the BUSY channels and reconfigure the operating bandwidth to transmit CTS frames using only the IDLE channels.

[0017] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0018] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0019] Figure 3 is a diagram illustrating a general link setup process.

[0020] FIG. 4 illustrates an example of a multi-link (ML).

[0021] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0022] Figure 6 is a diagram showing the arrangement of resource units (RU) used for a 20 MHz PPDU.

[0023] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0024] Figure 8 is a diagram showing the arrangement of resource units (RU) used for an 80 MHz PPDU.

[0025] Figure 9 shows the operation according to UL-MU.

[0026] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0027] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0028] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0029] FIG. 13 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0030] Figure 14 illustrates operation according to a conventional STX operation.

[0031] Figure 15 illustrates an example of C-OFDMA (Coordinated OFDMA).

[0032] Figure 16 illustrates an example of Coordinated Beamforming (CBF).

[0033] Figure 17 illustrates an example of AP selection.

[0034] Figure 18 illustrates an example of JTX / JT.

[0035] Figure 19 shows an example of the operation of a MU-RTS TXS trigger frame with a value of 2 in the TXOP Sharing Mode subfield.

[0036] Figure 20 shows an example of Co-TDMA operation.

[0037] Figure 21 illustrates an example of a CTS frame transmission failure.

[0038] FIG. 22 illustrates an example of MU-RTS TXS TF / CTS frame switching in Co-TDMA having bandwidth signaling TA.

[0039] FIG. 23 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0040] FIG. 24 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0041] FIG. 25 is a flowchart illustrating a procedure for transmitting a CTS frame in response to a MU-RTS TXS trigger frame in a Co-TDMA operation having a bandwidth signaling TA according to the present embodiment.

[0042] FIG. 26 is a flowchart illustrating the procedure for receiving a CTS frame in response to a MU-RTS TXS trigger frame in a Co-TDMA operation having a bandwidth signaling TA according to the present embodiment.

[0043] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0044] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B, or C.”

[0045] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0046] Additionally, parentheses used in this specification may mean “for example.” Specifically, when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.” In other words, the “control information” of this specification is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be proposed as an example of “control information.” Furthermore, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.”

[0047] Additionally, as used herein, “a / an” may mean “at least one” or “one or more.” Also, terms ending in “(s)” may mean “at least one” or “one or more.”

[0048] Additionally, the expressions “based on,” “on the basis of,” or “according to” as used herein mean “based at least in part on,” and do not mean “based only on one.”

[0049] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0050] The following examples of this specification may be applied to various wireless communication systems. For example, the following examples of this specification may be applied to wireless local area network (WLAN) systems. For example, this specification may be applied to IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification may be applied to Ultra High Reliability (UHR) standards or next-generation wireless LAN standards that enhance IEEE 802.11bn. In addition, the examples of this specification may be applied to mobile communication systems. For example, they may be applied to mobile communication systems based on Long Term Evolution (LTE) and its evolution based on 3GPP (3rd Generation Partnership Project) standards.

[0051] To explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0052] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0053] 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 this specification may also be referred to by various names such as mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, or simply user. The STA (110, 120) of this specification may also be referred to by various names such as network, base station, Node-B, Access Point (AP), repeater, router, relay, etc. The STA (110, 120) of this specification may also be referred to by various names such as receiving apparatus, transmitting device, receiving STA, transmitting STA, receiving device, transmitting device, etc.

[0054] For example, the STA (110, 120) can perform the role of an access point (AP) or a non-AP. That is, the STA (110, 120) of this specification can perform the functions of an AP and / or a non-AP. In this specification, an AP may also be indicated as an AP STA.

[0055] The STA (110, 120) of this specification may support various communication standards other than the IEEE 802.11 standard. For example, it may support communication standards according to 3GPP standards (e.g., LTE, LTE-A, 5G NR standards). In addition, the STA of this specification may be implemented in various devices such as mobile phones, vehicles, and personal computers. Furthermore, the STA of this specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving.

[0056] In this specification, the STA (110, 120) may include a medium access control (MAC) that complies with the provisions of the IEEE 802.11 standard and a physical layer interface for the wireless medium.

[0057] Based on side drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0058] The first STA (110) may include a processor (111), 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.

[0059] The transceiver (113) of the first STA performs the operation of transmitting and receiving signals. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0060] 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 transmitted signal, and perform control for transmitting the signal. The memory (112) of the AP can store the signal received through the transceiver (113) (i.e., the received signal) and the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0061] For example, the second STA (120) can perform the intended operation of a Non-AP STA. For example, the non-AP transceiver (123) performs the operation of transmitting and receiving signals. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0062] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmitted signal, and perform control for transmitting the signal. The memory (122) of the Non-AP STA can store the signal received through the transceiver (123) (i.e., the received signal) and can store the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0063] For example, the operation of the device indicated as AP in the following specification may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (111) of the first STA (110), and related signals may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). Additionally, control information related to the operation of the AP or the transmission / reception signals of the AP may be stored in the memory (112) of the first STA (110). Additionally, if the second STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (121) of the second STA (120), and related signals may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or the transmission / reception signals of the AP can be stored in the memory (122) of the second STA (110).

[0064] For example, the operation of a device indicated as non-AP (or User-STA) in the following specification may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is non-AP, the operation of the device indicated as non-AP is controlled by the processor (121) of the second STA (120), and related signals may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signals 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 the device marked as non-AP is controlled by the processor (111) of the first STA (110), and the related signal can be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signal of the AP can be stored in the memory (112) of the first STA (110).

[0065] In the following specification, a device referred to as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, a device indicated without specific drawing symbols as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may also refer to the STA (110, 120) of FIG. 1. For example, in the following example, the operation of various STAs transmitting and receiving signals (e.g., PPDU) may be performed by the transceivers (113, 123) of FIG. 1. Additionally, in the following example, 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 processors (111, 121) of FIG. 1.For example, an example of an operation to generate a transmission / reception signal or to perform data processing or operations in advance for a transmission / reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of sub-fields (SIG, STF, LTF, Data) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 4) a power control operation and / or power saving operation applied to the STA; and 5) an operation related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. In addition, in the following example, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals can be stored in the memory (112, 122) of FIG. 1.

[0066] The device / STA of the aforementioned supplementary drawing (a) of FIG. 1 can be modified as shown in supplementary drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of this specification will be described based on supplementary drawing (b) of FIG. 1.

[0067] For example, the transceiver (113, 123) shown in side drawing (b) of FIG. 1 can perform the same function as the transceiver shown in side drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) shown in side drawing (b) of FIG. 1 may include a processor (111, 121) and a memory (112, 122). The processor (111, 121) and memory (112, 122) shown in side drawing (b) of FIG. 1 can perform the same function as the processor (111, 121) and memory (112, 122) shown in side drawing (a) of FIG. 1 described above.

[0068] 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, AP (Access Point), 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) shown in side drawings (a) / (b) of FIG. 1, or the processing chip (114, 124) shown in side drawing (b) of FIG. 1. That is, the technical features of the present specification may be performed in the STA (110, 120) shown in side drawings (a) / (b) of FIG. 1, or only in the processing chip (114, 124) shown in side drawing (b) of FIG. 1. For example, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal generated in the processor (111, 121) shown in side drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) shown in side drawings (a) / (b) of FIG. 1. Alternatively, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal to be transmitted from the processing chip (114, 124) shown in side drawing (b) of FIG. 1 is generated to the transceiver (113, 123).

[0069] For example, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal being received by the transceivers (113, 123) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceivers (113, 123) shown in side view (a) of FIG. 1 being acquired by the processor (111, 121) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceivers (113, 123) shown in side view (b) of FIG. 1 being acquired by the processing chip (114, 124) shown in side view (b) of FIG. 1.

[0070] Referring to side view (b) of FIG. 1, software code (115, 125) may be included in 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.

[0071] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. 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 EXYNOSTM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, or a processor enhanced therefrom.

[0072] In this specification, an uplink may refer to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. may be transmitted through the uplink. Additionally, in this specification, a downlink may refer to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. may be transmitted through the downlink.

[0073] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0074] The top of Figure 2 shows the structure of the basic service set (BSS) infrastructure of IEEE (Institute of Electrical and Electronic Engineers) 802.11.

[0075] The top of Figure 2 shows the structure of the basic service set (BSS) infrastructure of IEEE (Institute of Electrical and Electronic Engineers) 802.11.

[0076] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter BSS). The BSS (200, 205) is a set of APs and STAs, such as an AP (access point, 225) and STA1 (Station, 200-1), that can communicate with each other by successfully synchronizing, and is not a concept referring to a specific area. The BSS (205) may include one or more STAs (205-1, 205-2) that can be combined with one AP (230).

[0077] The BSS may include at least one STA, an AP (225, 230) that provides a distribution service, and a distribution system (DS, 210) that connects multiple APs.

[0078] A distributed system (210) can implement an extended service set (ESS, 240) by connecting multiple BSSs (200, 205). The term ESS (240) may be used to refer to a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) may have the same service set identification (SSID).

[0079] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) with another network (e.g., 802.X).

[0080] In a BSS like the one at the top 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 between STAs and perform communication without APs (225, 230). A network that establishes a network between STAs and performs communication without APs (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0081] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0082] 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 performs management functions centrally. 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 since access to the distributed system is not allowed, they form a self-contained network.

[0083] Figure 3 is a diagram illustrating a general link setup process.

[0084] In the described S310 step, the STA can perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0085] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, the STA performing the scanning moves between channels and transmits a probe request frame to search for nearby APs, and waits for a response. The responder transmits a probe response frame as a response to the probe request frame to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned. In a BSS, the AP becomes the responder because it transmits the beacon frame, whereas in an IBSS, the responder is not constant because STAs within the IBSS take turns transmitting the beacon frame. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning in the same way (i.e., transmit and receive probe request / response on channel 2).

[0086] Although not shown in the example of Fig. 3, scanning operations may also be performed using a passive scanning method. An STA performing scanning based on passive scanning can wait for a beacon frame while switching between channels. A beacon frame is one of the management frames in IEEE 802.11, which announces the presence of a wireless network and is periodically transmitted to allow a scanning STA to find the wireless network and join it. In a BSS, the AP performs the role of periodically transmitting beacon frames, while in an IBSS, STAs within the IBSS take turns transmitting beacon frames. When a scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. An STA that has received a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner.

[0087] The STA that discovered the 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 later. The authentication process of S320 may include the STA sending an authentication request frame to the AP, and the AP sending an authentication response frame to the STA in response. The authentication frame used in the authentication request / response corresponds to a management frame.

[0088] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, RSN (Robust Security Network), Finite Cyclic Group, etc.

[0089] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can determine whether to allow authentication for the STA. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0090] A successfully authenticated STA may perform an association process based on step S330. The association process includes the STA sending an association request frame to the AP, and in response, the AP sending an association response frame to the STA. For example, the association request frame may include information regarding various capabilities, beacon listen interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, a connection response frame may include information related to various capabilities, status code, AID (Association ID), support rate, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS map, etc.

[0091] Subsequently, 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 4-way handshake via an EAPOL (Extensible Authentication Protocol over LAN) frame.

[0092] FIG. 4 illustrates an example of a multi-link (ML).

[0093] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate through a multi-link. The MLDs can be classified into an AP MLD containing multiple AP STAs and a non-AP MLD containing multiple non-AP STAs. That is, the AP MLD may include affiliated APs (i.e., AP STAs), and the non-AP MLD may include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0094] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be assigned to the first and second links. The first and second multilinks may be identified by 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 link may be configured in different bands.

[0095] The AP MLD of FIG. 4 includes three affiliated APs. In one 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 one 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. Additionally, in one 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. Additionally, in one 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.

[0096] In one example of FIG. 4, AP1 can initiate a multilink setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In one example of FIG. 4, non-AP STA1 can transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) shown in FIG. 4 may be the same as the AP shown in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) shown in FIG. 4 may be the same as the STA shown in FIG. 1 and / or FIG. 2 (i.e., user-STA or non-AP STA).

[0097] The specific features of this specification 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.

[0098] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0099] The STAs of this specification (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) can transmit and / or receive the PPDU of FIG. 5. The PPDU described in this specification may have the structure of FIG. 5, for example. Additionally, the PPDU described in this specification, the Ultra High Reliability (UHR) PPDU, may be referred to by various names such as transmit PPDU, receive PPDU, first type or N type PPDU. The PPDU described in this specification may be used in WLAN systems defined according to IEEE 802.11bn and / or next-generation WLAN systems that improve upon IEEE 802.11bn.

[0100] The PPDU of FIG. 5 may be related to various PPDU types used in a UHR system. For example, the example of FIG. 5 may be used for at least one of SU (single-user) mode / type / transmission, MU (multi-user) mode / type / transmission, and NDP (null data packet) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the illustrated Data field may be omitted. If the PPDU of FIG. 5 is used for TB (Trigger-based) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that receives a Trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU in which the UHR-SIG is omitted in the example of FIG. 5.

[0101] In FIG. 5, L-STF to UHR-LTF can be called a preamble or physical preamble and can be generated / transmitted / received / acquired / decoded at the physical layer (included in the transmitting / receiving STA).

[0102] Each block illustrated in FIG. 5 may be referred to as a field / subfield / signal, etc. As illustrated in FIG. 5, the names of these fields / subfields / signals may be 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.

[0103] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in Fig. 5 can be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields can 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 can be displayed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields can be displayed in units of 78.125 kHz.

[0104] The PPDU of Fig. 5, L-LTF and L-STF, may be the same as conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0105] The L-SIG field of FIG. 5 may contain, 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 contain information regarding the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, 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 a UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is an 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, or 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 a UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0106] For example, a (non-AP and AP) STA can apply BCC encoding based on a code rate of 1 / 2 to 24 bits of information in the L-SIG field. Subsequently, the transmitting STA can obtain 48 bits of BCC encoding. BPSK modulation can be applied to the 48 bits of encoding to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarrier {subcarrier indices -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. Consequently, the 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA can additionally map the signal of {-1, -1, -1, 1} to the subcarrier index {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0107] For example, the (non-AP and AP) STA can generate an RL-SIG that is identical to the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving (non-AP and AP) STA can determine that the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of the RL-SIG. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the HE PPDU, EHT PPDU, or UHR PPDU if the RL-SIG is present. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the non-HT PPDU, HT PPDU, or VHT PPDU if the RL-SIG is not present. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

[0108] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be referred to by various names such as the first SIG field, first SIG, first type SIG, control signal, control signal field, first (type) control signal, common control field, and common control signal.

[0109] U-SIG may contain N bits of information and may contain information to identify the type of EHT PPDU. For example, U-SIG may be constructed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol for U-SIG (e.g., OFDM symbol) may have a duration of 4 us. Each symbol of U-SIG may be used to transmit 26 bits of information. For example, each symbol of U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0110] For example, A bit information (e.g., 52 un-coded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bit information (e.g., 26 un-coded bits) of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bit information (e.g., 26 un-coded bits) of the total A bit information. For example, the transmitting STA can obtain the 26 un-coded bits included in each U-SIG symbol. The transmitting STA can generate 52-coded bits by performing convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 and can perform interleaving on the 52-coded bits. The transmitting STA can generate 52 BPSK symbols assigned to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. 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. 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.

[0111] For example, A bit information (e.g., 52 un-coded bits) transmitted by U-SIG may include a CRC field (e.g., a field of 4 bits) and a tail field (e.g., a field of 6 bits). The CRC field and the tail field may be transmitted through a second symbol of U-SIG. The CRC field may be generated based on 26 bits assigned to the first symbol of U-SIG and the remaining 16 bits within the second symbol excluding the CRC / tail field, and may be generated based on a conventional CRC calculation algorithm. Additionally, the tail field may be used to terminate the trellis of a convolutional decoder and may be set, for example, to "000000".

[0112] A bit information (e.g., 52 un-coded bits) transmitted by 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 may be assigned only to the first symbol of U-SIG, or the version-independent bits may be assigned to both the first and second symbols of U-SIG. For example, the version-independent bits and the version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0113] For example, the version-independent bits of U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmitted and received PPDU. For example, a first value of the 3-bit PHY version identifier (e.g., a value of 000) may indicate that the transmitted and received PPDU is an EHT PPDU. Additionally, a second value of the 3-bit PHY version identifier (e.g., a value of 001) may indicate that the transmitted and received PPDU is a UHR PPDU.

[0114] In other words, when an (AP / non-AP) STA transmits an EHT PPDU, it can set a 3-bit PHY version identifier to a first value. In other words, a receiving (AP / non-AP) STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value, and can determine that the received PPDU is a UHR PPDU based on the PHY version identifier having the second value.

[0115] 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 is related to UL communication, and the second value of the UL / DL flag field is related to DL communication.

[0116] For example, the version-independent bits of U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0117] For example, if the UHR PPDU is classified into various types (e.g., type related to SU transmission (performed based on UL or DL), type related to DL transmission, type related to NDP transmission, type related to DL non-MU-MIMO, type related to DL MU-MIMO, type related to Multi-AP operation, type related to Co-BF (Coordinated beamforming) and SR (Spatial Reuse), type related to C-OFDMA (Coordinated OFDMA), type related to Co-TDMA (Coordinated TDMA)), information regarding the type of the EHT PPDU (e.g., 2-bit or 3-bit information) may be included in the version-dependent bits of the U-SIG.

[0118] For example, U-SIG may include: 1) a bandwidth field containing information regarding bandwidth; 2) a field containing information regarding the MCS technique applied to UHR-SIG; 3) an indication field containing information regarding whether the dual subcarrier modulation (DCM) technique is applied to UHR-SIG; 4) a field containing information regarding the number of symbols used for UHR-SIG; 5) a field containing information regarding whether UHR-SIG is generated across the entire band; 6) a field containing information regarding the type of UHR-LTF / STF; and 7) information regarding a field indicating the length of UHR-LTF and CP length.

[0119] Preamble puncturing may be applied to the PPDU of Fig. 5. Preamble puncturing means applying puncturing to a portion of the total band of the PPDU (e.g., a secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA applies puncturing to the secondary 20 MHz band within the 80 MHz band and can transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

[0120] For example, the pattern of preamble puncturing can be pre-set. For example, when a first puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band within an 80 MHz band. For example, when a second puncturing pattern is applied, puncturing may be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band within an 80 MHz band. For example, when a third puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band included in a primary 80 MHz band within a 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, within the 160 MHz band (or 80+80 MHz band), the primary 40 MHz band included in the primary 80 MHz band is present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0121] 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.

[0122] 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 configured individually in 80 MHz units. 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 regarding a 160 MHz bandwidth, and the second field of the second U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern). Meanwhile, the UHR-SIG following the first U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern), and the UHR-SIG following the second U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding a preamble puncturing pattern).

[0123] Additionally or generally, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. 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).

[0124] 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 may contain different U-SIGs.

[0125] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0126] UHR-SIG provides additional signals to the U-SIG field, enabling the STA to interpret / decode the UHR PPDU. The UHR-SIG field may include U-SIG overflow bits that apply commonly to all users. Additionally, the UHR-SIG field contains resource allocation information, making it possible for the STA to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0127] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on a RU (resource unit) defined by a plurality of subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through a RU (resource unit) defined by a plurality of subcarriers / tones.

[0128] FIG. 6 is a diagram showing the arrangement of resource units (RUs) used for a 20 MHz PPDU. That is, 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. 6.

[0129] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) may be arranged. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. Additionally, seven DC tones are inserted into the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on the left and right sides of the DC band. Furthermore, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for a receiving station, i.e., a user.

[0130] Meanwhile, the RU arrangement of Fig. 6 is utilized not only for situations involving multiple users (MU) but also for situations involving a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 4, and in this case, three DC tones can be inserted.

[0131] In the example of FIG. 6, various sizes of RUs, namely 26-RU, 52-RU, 106-RU, 242-RU, etc., are proposed. Since the specific size 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 this specification, N-RU may be indicated as N-tone RU, etc. For example, 26-RU may be indicated as 26-tone RU.

[0132] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0133] Just as various sizes of RUs were used in the example of FIG. 6, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc., may also be used in the example of FIG. 7. Additionally, 5 DC tones may be inserted at the center frequency, 12 tones may be used as guard bands in the leftmost band of the 40 MHz band, and 11 tones may be used as guard bands in the rightmost band of the 40 MHz band.

[0134] In addition, as described, 484-RU may be used when used for a single user. Meanwhile, the specific number of RUs may be changed, as in the example of FIG. 6.

[0135] FIG. 8 is a diagram showing the arrangement of resource units (RUs) used for an 80 MHz PPDU. The arrangement of resource units (RUs) used in this specification may be varied. For example, the arrangement of resource units (RUs) used in the 80 MHz band may be varied.

[0136] FIG. 9 illustrates the operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can establish a channel connection through contending (i.e., Backoff operation) and transmit a Trigger frame (930). That is, the transmitting STA (e.g., AP) can transmit a PPDU containing the Trigger frame (930). When the PPDU containing the Trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0137] TB PPDUs (941, 942) may be transmitted at the same time and may be transmitted from multiple STAs (e.g., User STAs) with AIDs indicated within the Trigger frame (930). The ACK frame (950) for the TB PPDU may be implemented in various forms.

[0138] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0139] The 2.4 GHz band may be referred to by other names, such as the first band (band). Additionally, 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 located between 2.4 and 2.5 GHz) are used / supported / defined.

[0140] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz channels 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 to channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned to channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned to channel index N may be (2.407 + 0.005*N) GHz. Channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of channel indices and center frequencies may change.

[0141] FIG. 10 illustrates four channels within a 2.4 GHz band as an example. The illustrated first frequency range (1010) to fourth frequency range (1040) may each include one channel. For example, the first frequency range (1010) may include channel 1 (a 20 MHz channel having index 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency range (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency range (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency range (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0142] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0143] The 5 GHz band may be referred to by other names such as the second band / band. The 5 GHz band may refer to a frequency range in which channels with a center frequency of 5 GHz or higher 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. 11 may be changed.

[0144] Multiple channels within the 5 GHz band include UNII (Unlicensed National Information Infrastructure)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency regions referred to as UNII Mid and UNII-2 Extended. UNII-3 may be referred to as UNII-Upper.

[0145] Multiple channels may be configured within the 5 GHz band, and the bandwidth of each channel may be varied, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency range within UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency range may be divided into four channels through a 40 MHz frequency range. The 5170 MHz to 5330 MHz frequency range may be divided into two channels through an 80 MHz frequency range. Alternatively, the 5170 MHz to 5330 MHz frequency range may be divided into one channel through a 160 MHz frequency range.

[0146] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0147] The 6 GHz band may be referred to by other names such as the third band / band. The 6 GHz band may refer to a frequency range in which channels with a center frequency of 5.9 GHz or higher are used / supported / defined. The specific figures shown in FIG. 12 are subject to change.

[0148] For example, the 20 MHz channel of FIG. 12 can be defined starting from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 may have index 1 (or channel index, channel number, etc.), and the center frequency may be assigned as 5.945 GHz. That is, the center frequency of the index N channel may be determined as (5.940 + 0.005*N) GHz.

[0149] Accordingly, the indices (or channel numbers) of the 20 MHz channel in FIG. 12 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, 197, It may be 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule described above, the index of the 40 MHz channel of FIG. 12 may 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.

[0150] FIG. 13 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0151] The device illustrated in FIGS. 1 to 4 (e.g., AP STA, non-AP STA) can be modified as in FIG. 13. The transceiver (630) of FIG. 13 may be identical to the transceiver (113, 123) of FIG. 1. The transceiver (630) of FIG. 13 may include a receiver and a transmitter.

[0152] The processor (610) of FIG. 13 may be the same as the processor (111, 121) of FIG. 1. Or, the processor (610) of FIG. 13 may be the same as the processing chip (114, 124) of FIG. 1.

[0153] The memory (150) of FIG. 13 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (150) of FIG. 13 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0154] Referring to FIG. 13, a power management module (611) manages power for a processor (610) and / or a transceiver (630). A battery (612) supplies power to the power management module (611). A display (613) outputs results processed by the processor (610). A keypad (614) receives input to be used by the processor (610). The keypad (614) may be displayed on the display (613). A SIM card (615) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and associated keys used to identify and authenticate a subscriber in a mobile device such as a mobile phone and a computer.

[0155] Referring to FIG. 13, the speaker (640) can output sound-related results processed by the processor (610). The microphone (641) can receive sound-related inputs to be used by the processor (610).

[0156] The Multi-AP operation applicable to this specification is described below.

[0157] The above Multi-AP operation refers to a communication technique involving multiple APs in a WLAN. For example, the above Multi-AP operation may refer to an operation in which one or more APs transmit and receive information to one or more STAs. In contrast to the above Multi-AP operation, existing techniques may be expressed using various terms such as STX (Single Transmission). For example, the above STX operation may refer to a method in which a single BSS AP communicates with a single BSS STA. When communication is performed based on the above STX operation, interference may occur with adjacent APs (e.g., APs located in overlapping BSSs). Due to this interference, a problem may arise in which the transmission and reception performance of cell-edge users (e.g., non-AP STAs located at the edge of the BSS) is reduced.

[0158] FIG. 14 illustrates operation according to a conventional STX operation. As illustrated, interference between STA and AP may occur due to AP1 and AP2 being adjacent to each other.

[0159] To improve the above STX operation, the above Multi-AP operation is newly proposed. The above Multi-AP operation may be based on a technique that reduces various interferences, such as Inter-symbol interference (ISI), through coordination with neighboring APs (e.g., APs located in overlapping BSSs).

[0160] In Figure 14, STA1 and AP1 are included in the BSS, and STA2 and AP2 can be included in the OBSS (Overlapping Basic Service Set). That is, STA2 is an un-associated STA to AP1, and STA1 is an un-associated STA to AP2.

[0161] For example, the above Multi-AP operation may be classified into various technologies, types, formats, protocols, etc. For example, the above Multi-AP operation may include Co-TDMA (Coordinated TDMA) which distinguishes wireless resources allocated to multiple APs based on the time axis (time domain). Additionally or generally, the above Multi-AP operation may include C-OFDMA (Coordinated OFDMA) which distinguishes wireless resources allocated to multiple APs based on the frequency axis (time domain). Additionally or generally, the above Multi-AP operation may include Co-SR (Coordinated Spatial Reuse) which applies Spatial Reuse (SR) to at least one AP. Additionally or generally, the above Multi-AP operation may include Coordinated beamforming (CBF) / nulling which transmits by nulling interference occurring from neighbors (e.g., adjacent AP / STA, and / or OBSS AP / OBSS STA). Additionally or generally, the Multi-AP operation may include AP selection in which an AP among adjacent APs with good channel conditions (e.g., at least one AP located within a BSS or OBSS with excellent channel conditions) performs transmission. Additionally or generally, the Multi-AP operation may include Joint Transmission (JTX) or Joint Transmission (JT) in which multiple APs (e.g., multiple APs included in the same BSS / OBSS, or multiple APs included in different BSS / OBSSs) coordinate to perform simultaneous transmission and reception, and the JTX / JT may be implemented based on Joint Beamforming or Joint MU-MIMO.

[0162] FIG. 15 illustrates an example of C-OFDMA (Coordinated OFDMA). The illustrated AP1 can transmit a PPDU / signal to STA1, and AP2 can transmit a PPDU / signal to STA2. Transmission from AP1 and transmission from AP2 can be performed in the same / overlapping time interval. Transmission from AP1 to STA1 can be performed based on a first frequency band, and transmission from AP2 to STA2 can be performed based on a second frequency band different from the second frequency band. For example, in FIG. 15, STA1 and AP1 may be included in BSS, and STA2 and AP2 may be included in OBSS. That is, STA2 may be an un-associated STA to AP1, and STA1 may be an un-associated STA to AP2.

[0163] Although not shown in FIG. 15, an example of Co-TDMA (Coordinated TDMA) is also possible. For example, the acquired TXOP can be divided into specific time units (e.g., slots), and the divided slots can be sequentially assigned to multiple different APs.

[0164] The example of C-OFDMA described above may be further modified as follows. For example, an AP that has acquired a TXOP (e.g., AP1) may share frequency resources with at least one surrounding AP (e.g., AP2 present in BSS / OBSS). For example, the shared frequency resources may be defined in units of resource units (RU) or subchannels, and for example, considering flexibility, frequency resources may be shared by AP1 to AP2 in units of 20 / 40 / 80 MHz subchannels or 242 / 484 / 996-tone RUs.

[0165] AP1, which performs C-OFDMA, can perform the role of a sharing AP or a Master AP. That is, AP1 can request at least one surrounding AP (e.g., AP2 in BSS / OBSS) to report information about the channel and / or buffer status. Based on this, AP1 acquires a TXOP and can share a portion of the frequency resources (e.g., a 20 MHz subchannel or a specific size RU) with at least one surrounding AP (e.g., AP2 in BSS / OBSS) within all or part of the time interval associated with the TXOP.

[0166] FIG. 16 illustrates an example of Coordinated Beamforming (CBF). The illustrated AP1 can transmit a PPDU / signal to STA1, and AP2 can transmit a PPDU / signal to STA2. Transmission from AP1 and transmission from AP2 can be performed in the same / overlapping time intervals. Transmission from AP1 and transmission from AP2 can be performed through the same / overlapping frequency bands. To reduce interference caused by AP1 to STA2, AP1 can perform nulling / beamforming toward STA2, and to reduce interference caused by AP2 to STA1, AP2 can perform nulling / beamforming toward STA1. For example, such nulling / beamforming can be implemented by positioning a radiation null to a neighboring unassociated STA. The aforementioned nulling / beamforming can make a specific AP invisible to a neighboring unassociated STA. For example, the aforementioned nulling / beamforming can make AP1 (or AP2) invisible to STA2 (or STA1).

[0167] For example, in Fig. 16, STA1 and AP1 may be included in BSS, and STA2 and AP2 may be included in OBSS. That is, STA2 may be an un-associated STA to AP1, and STA1 may be an un-associated STA to AP2.

[0168] Although not shown in FIG. 16, control signals (e.g., coordination frames) for nulling / beamforming between AP1 and STA2 and / or nulling / beamforming between AP2 and STA1 can be transmitted and received through a backhaul link between AP1 and AP2.

[0169] FIG. 17 illustrates an example of AP selection. The illustrated AP2 is determined to have better channel conditions than AP1. AP1 transmits its data / signal to AP2 via a backhaul link, and AP2 can transmit a signal to STA1 instead of AP1. For example, in FIG. 17, STA1 and AP1 may be included in BSS, and STA2 and AP2 may be included in OBSS. That is, STA2 may be an un-associated STA to AP1, and STA1 may be an un-associated STA to AP2.

[0170] FIG. 18 illustrates an example of JTX / JT. The illustrated AP1 can perform transmission to STA1 together with AP2. For example, the PPDU / signal transmitted from AP2 to STA1 may be wholly or partially identical to the PPDU / signal transmitted from AP1 to STA1. For example, the PPDU / signal transmitted from AP2 to STA1 may be transmitted simultaneously through a frequency band that is identical to or overlaps with the PPDU / signal transmitted from AP1 to STA1. For example, the PPDU / signal transmitted from AP2 to STA1 may be a signal transmitted from AP1 via a backhaul link. For example, in FIG. 18, STA1 and AP1 may be included in a BSS, and STA2 and AP2 may be included in an OBSS. That is, STA2 may be an un-associated STA to AP1, and STA1 may be an un-associated STA to AP2.

[0171] More specifically, in FIG. 18, AP1 transmits a coordination request (or various names such as first request, control request, etc.) to AP2 and receives a coordination response (or various names such as first response, control response, etc.) from AP2. Through the exchange of the request / response, information regarding coordination between AP1 and AP2 (e.g., information regarding whether AP1 and AP2 will perform simultaneous transmission to STA1), information regarding the time when coordination begins, information regarding the time when AP1 and AP2 start simultaneous transmission to STA1, and information regarding data shared between AP1 and AP2 can be exchanged. AP1 can share its data with AP2 via a backhaul link. Subsequently, AP1 transmits a coordination trigger frame (or various names such as trigger frame, etc.) to AP2 and can perform simultaneous transmission to STA1 based on the trigger frame.

[0172] <Examples Applicable to the Present Specification>

[0173] Although a large number of APs are installed in close proximity to each other to enable terminals to maintain continuous WLAN connectivity over a wider area, issues such as radio interference and transmission collisions between APs may occur as the BSSs of multiple APs overlap. To resolve these issues, various technologies for coordinating APs in frequency, time, and spatial domains (e.g., RU selection, joint transmission, nulling, etc.) have been proposed, and attention must also be paid to the various issues that may arise during cooperation between APs.

[0174] In EHT (802.11be), a technique was proposed to allocate a portion of the time within the TXOP acquired by the AP to support Peer-to-Peer (P2P) transmission to non-AP STAs. To this end, a new TXOP Sharing Mode subfield was defined within the Common Info field of the existing MU-RTS Trigger frame, and a MU-RTS (Multi User-Request To Send) Trigger frame when this value is non-zero is referred to as a MU-RTS TXOP Sharing (TXS) Trigger frame (TF). If the value of TXOP Sharing mode is 1, the non-AP STA supports one or more (non-TB) PPDU transmissions to the AP, and if the value of TXOP Sharing mode is 2, the non-AP STA supports P2P transmission in addition to (non-TB) PPDU transmission to the AP.

[0175] Figure 19 shows an example of the operation of a MU-RTS TXS trigger frame with a value of 2 in the TXOP Sharing Mode subfield.

[0176] FIG. 19 shows an example of operation when the TXOP Sharing mode value is 2. When the AP transmits a MU-RTS TXS TF containing time allocation information (Time allocated in MU-RTS TXS Trigger Frame in FIG. 19) to non-AP STA 1, Non-AP STA 1 responds to this with a CTS (Clear-To-Send) and can then perform P2P transmission to non-AP STA 2.

[0177] Figure 20 shows an example of Co-TDMA operation.

[0178] In the current standard, Coordinated TDMA (Co-TDMA) is defined by extending the existing TXS protocol to Multi-AP coordination (MAPC) to perform TXOP sharing / allocation between cooperative APs. Figure 20 illustrates an example of Co-TDMA operation between cooperative APs. In this case, the AP in the existing Triggered TXS protocol can be replaced with the AP sharing the TXOP in MAPC operation, and the STA in the existing Triggered TXS protocol can be replaced with the AP receiving the shared TXOP in MAPC operation. Based on the definition in 802.11bn, the AP transmitting the MU-RTS TXS TF for time / TXOP allocation is referred to as the Sharing AP (SAP) or Coordinating AP, and the AP finally receiving the time / TXOP allocation is referred to as the Coordinated AP (CAP). Here, the designation SAP does not limit the entity sharing the TXOP to only the AP STA, but also includes non-AP STAs that share the TXOP. In addition, the designation CAP does not limit the entity sharing the TXOP to only AP STAs, but also includes non-AP STAs that share the TXOP (or perform transmission and reception with an AP STA that shares the TXOP). Furthermore, frame exchanges with non-AP STAs or SAPs belonging to the CAP BSS during the time allocated to the CAP are referred to as the CAP's BSS frame exchange (FE). For example, data frame transmissions and block ACK frame responses following RTS / CTS frame exchanges between the CAP and non-AP STAs, UL data frame transmissions by non-AP STAs in response to trigger frames transmitted from the CAP, or data frame transmissions by the CAP in response to trigger frames transmitted from the SAP may be performed.

[0179] The description of Multi-AP Coordination (MAPC) is as follows.

[0180] MAPC is a framework in which multiple APs cooperate to reduce interference, improve channel utilization efficiency, and enhance reliability and latency; key schemes may include Co-BF (Coordinated Beamforming), Co-SR (Coordinated Spatial Reuse), Co-TDMA (Coordinated TDMA), Co-RTWT (Coordinated Restricted Target Wake Time), and Co-CR (Coordinated Channel Reservation).

[0181] Common procedures for MAPC include the MAPC Discovery procedure and the MAPC Agreement Negotiation procedure. In the MAPC Discovery procedure, an AP can notify other APs of its MAPC capabilities and parameters through the MAPC Discovery Request / Response frame or the management frame. The MAPC Agreement Negotiation procedure may be a process for negotiating, establishing, updating, or terminating an agreement on a specific MAPC scheme among APs. Detailed procedures for the MAPC agreement may include forming the MAPC agreement, assigning an AP ID to identify cooperating APs, updating parameters of the existing MAPC agreement, and terminating the MAPC agreement.

[0182] To clarify the terminology, the AP initiating the above MAPC (or MAPC negotiation for at least one MAPC technique) may be referred to as the MAPC requesting AP or the coordinating AP. The AP responding to the above MAPC requesting AP may be referred to as the MAPC responding AP or the coordinated AP. The above coordinating AP is an AP that shares a portion of the TXOP (transmission opportunity) resources by allocating a time portion to the above coordinated AP or by allowing simultaneous transmission as part of the MAPC procedure.

[0183] 1. Co-TDMA-based TXOP Sharing and Return Procedure

[0184] 1) Basic Concepts of Co-TDMA

[0185] Coordinated Time Division Multiple Access (Co-TDMA) is a mechanism in which one AP (hereinafter Co-TDMA coordinating AP) sequentially allocates a portion of the TXOPs it has acquired to one or more other APs (hereinafter Co-TDMA coordinated APs) on a time-by-time basis, so that each AP can independently perform PPDU exchanges during that time.

[0186] Co-TDMA is performed only among APs that satisfy the following conditions.

[0187] - Both APs will support the Co-TDMA function (dot11CoTDMAOptionImplemented).

[0188] - A MAPC-based Co-TDMA agreement will exist between the two APs

[0189] - The primary 20 MHz channels of both BSSs will be identical.

[0190] - The two APs will not belong to the same collocated AP set.

[0191] If these preconditions are satisfied, APs can perform time division sharing of TXOPs through the Co-TDMA procedure.

[0192] 2) Overall structure of the Co-TDMA procedure

[0193] Co-TDMA is performed in the following three steps.

[0194] - Polling phase

[0195] - TXOP allocation phase

[0196] - TXOP return phase

[0197] Among these, the key steps directly related to the present specification are the TXOP allocation phase and the TXOP return phase.

[0198] 3) TXOP Allocation Phase

[0199] The Co-TDMA coordinating AP transmits a MU-RTS TXS Trigger frame to allocate a portion of the TXOPs it has acquired to one or more Co-TDMA coordinated APs.

[0200] This MU-RTS TXS Trigger frame is transmitted only to APs that satisfy the following conditions.

[0201] - The AP in question must have previously transmitted a Co-TDMA ICR (Initial Control Response) with a TXOP Sharing Solicited field of 1.

[0202] - The AP in question must have a non-collocated relationship with the coordinating AP.

[0203] In the MU-RTS TXS Trigger frame:

[0204] - The TXS Mode field is set to 2 to indicate that it is a Co-TDMA-based TXOP share.

[0205] - The AP ID of the assigned AP is set in AID12 of the User Info field.

[0206] - The Allocation Duration field specifies the time length allocated to the corresponding AP.

[0207] - The RU Allocation field specifies the 20 MHz channels that the AP will use.

[0208] The allocated time starts from the end point of the PPDU containing the MU-RTS TXS Trigger frame.

[0209] 4) Coordinated AP TXOP Usage Method

[0210] A Co-TDMA coordinated AP identified in a MU-RTS TXS Trigger frame can exchange one or more PPDUs during the allocated time.

[0211] At this time, the first PPDU must be a CTS (Clear-to-Send) frame, and it is transmitted as a CTS for the MU-RTS Trigger frame.

[0212] In addition, Co-TDMA coordinated APs are subject to the following limitations.

[0213] - Only 20 MHz channel(s) to which CTS was transmitted are available

[0214] - Subsequently, all PPDUs can only be transmitted on the same subchannel as the CTS used.

[0215] In other words, Co-TDMA forms a TXOP sharing structure in which not only the time but also the frequency (channel) is fixed.

[0216] 5) TXOP Return Phase (TXOP return)

[0217] A Co-TDMA coordinated AP can return any remaining TXOPs allocated to it to the coordinating AP if the coordinating AP supports and requests the return of TXOPs.

[0218] To this end, the coordinating AP is:

[0219] - Set the Rx TXOP Return Support field of the MAPC element to 1 to indicate support for the return function, and

[0220] - Request a return by setting the TXOP Return Solicited field to 1 in the Co-TDMA TB (Trigger Based) ICF (Initial Control Frame) or NTB (Non Trigger Based) ICF.

[0221] In response to this, the coordinated AP is:

[0222] - Transmit the MAPC TXOP Return frame within the allocated time, and

[0223] - Explicitly indicate the return of a TXOP by setting RDG / More PPDU = 0 in the CAS Control field within the HT Control field of the frame.

[0224] The coordinating AP responds to this TXOP return with an Ack frame. Through this procedure, ownership of the TXOP returns to the coordinating AP.

[0225] 6) Technical effects

[0226] According to this Co-TDMA-based TXOP sharing and return structure:

[0227] - TXOPs are leased and returned between APs through explicit signal exchange, and

[0228] - Time, frequency, AP identifier, and return status are all managed by control fields, and

[0229] - Since channels are fixed based on CTS, collisions and bandwidth interference can be prevented.

[0230] Therefore, Co-TDMA provides a distributed MAC layer control mechanism capable of precisely splitting / distributing / recovering TXOPs in a multi-AP environment.

[0231] 2. Definitions of Bandwidth Signaling TA, CH_BANDWIDTH_IN_NON_HT, and DYN_BANDWIDTH_IN_NON_HT

[0232] In non-HT physical layer transmission, the Transmitter Address (TA) field of the MAC header can be reinterpreted as a bandwidth signaling field when the Individual / Group (I / G) bit is set to 1. In this case, the TA field does not represent the MAC address of the transmitting STA, but acts as a bandwidth signaling TA indicating that the PPDU contains physical layer bandwidth information.

[0233] The Bandwidth signaling TA carries at least the CH_BANDWIDTH_IN_NON_HT parameter and optionally additionally carries the DYN_BANDWIDTH_IN_NON_HT parameter. CH_BANDWIDTH_IN_NON_HT indicates the channel bandwidth actually occupied by the PPDU transmitted in Non-HT format (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz in EHT systems). DYN_BANDWIDTH_IN_NON_HT indicates whether the PPDU is in a static bandwidth mode or a dynamic bandwidth mode where the bandwidth can change during transmission.

[0234] For example, if DYN_BANDWIDTH_IN_NON_HT is set to static, it means that the receiving STA responds in a fixed band according to the bandwidth provided by the transmitting STA. If DYN_BANDWIDTH_IN_NON_HT is set to dynamic, it means that the receiving STA responds by dynamically setting the band for the IDLE portion by performing CCA (Clear Channel Assessment) or PIFS check within the bandwidth provided by the transmitting STA.

[0235] Therefore, the bandwidth signaling TA provides an implicit signaling mechanism transmitted from the MAC layer to the PHY layer, enabling the receiving STA to determine the bandwidth and bandwidth operation mode of the corresponding PPDU before demodulating the Non-HT PPDU, thereby enabling the setting of the receiving RF (Radio Frequency), the configuration of the FFT (Fast Fourier Transform) window, and the appropriate setting of the demodulation resource.

[0236] 3. An example of CTS frame transmission failure

[0237] Figure 21 illustrates an example of a CTS frame transmission failure.

[0238] Basically, if CAP detects that 20 MHz subchannels containing the allocated RUs indicated in the RU Allocation field of the MU-RTS TXS TF received from SAP are busy, CAP cannot transmit solicited CTS frames.

[0239] Figure 21 shows an example of a CTS frame transmission failure that may occur when exchanging MU-RTS TXS TF / CTS frames between two APs with BSS operating channel widths of 320 MHz.

[0240] In the example of the left diagram in Fig. 21, the two APs have the same 320 MHz BSS operating channel width, and the SAP can transmit a MU-RTS TXS TF to the CAP with the RU Allocation field set to the maximum overlapped bandwidth of 320 MHz. At this time, since the MU-RTS TF basically does not have a bandwidth signaling TA (Transmitter Address), DYN_BANDWIDTH_IN_NON_HT can be considered static, and if the CAP's S160 is busy due to the OBSS (Overlapping Basic Service Set) STA, the CTS frame cannot be transmitted. Similarly, in the example of the right diagram in Fig. 21, even if the MU-RTS TXS TF is transmitted at the maximum overlapped bandwidth of the two APs, which is 160 MHz, the CTS frame cannot be transmitted if the CAP's S80 is busy.

[0241] Cases where some 20 MHz subchannels within the specified bandwidth are busy can occur more frequently in a Multi-AP environment due to hidden nodes, and as a result, the CAP cannot respond with a CTS frame, causing Co-TDMA to fail.

[0242] Accordingly, the present specification proposes a Co-TDMA operation using a bandwidth signaling TA. Specifically, the MU-RTS TXS TF transmitted to the CAP to allocate TXOP / time may have a bandwidth signaling TA, from which the value of DYN_BANDWIDTH_IN_NON_HT may be set dynamically.

[0243] Through Co-TDMA operation using the bandwidth signaling TA proposed in this specification, the CAP is able to transmit CTS frames that are smaller than or equal to the channel width indicated in the RU Allocation field within the User Info field of the MU-RTS TXS TF. This enables more successful exchanges of MU-RTS TXS TF / CTS frames and increases media utilization. Specific names proposed in this specification may be changed and are not limited.

[0244] 4. Example of MU-RTS TXS TF / CTS frame switching in Co-TDMA with bandwidth signaling TA

[0245] The existing MU-RTS Trigger frame is transmitted to request a CTS frame from one or more STAs simultaneously. Co-TDMA, as discussed in current standards, can be defined to request a CTS frame from only one AP to simplify protocol implementation. Therefore, if a MU-RTS TXS TF is transmitted to only one AP, the MU-RTS TXS TF can be implemented to have a bandwidth signaling TA.

[0246] FIG. 22 illustrates an example of MU-RTS TXS TF / CTS frame switching in Co-TDMA having bandwidth signaling TA.

[0247] In a PPDU containing a MU-RTS TXS TF having a bandwidth signaling TA, TXVECTOR parameters CH_BANDWIDTH_IN_NON_HT and DYN_BANDWIDTH_IN_NON_HT may exist. In Co-TDMA, if the DYN_BANDWIDTH_IN_NON_HT of the MU-RTS TXS TF that the SAP transmits to the CAP to allocate time / TXOP is set dynamically, the CAP may transmit a CTS frame as a response frame with a CH_BANDWIDTH set to be less than or equal to the channel width indicated in the RU Allocation field of the MU-RTS TXS TF.

[0248] Figure 22 shows an example of MU-RTS TXS TF / CTS frame exchange when transmitting a MU-RTS TXS TF with DYN_BANDWIDTH_IN_NON_HT set to dynamic with bandwidth signaling TA.

[0249] In the example of the left diagram of FIG. 22, the two APs have the same 320 MHz BSS operating channel width, and SAP can transmit a MU-RTS TXS TF to CAP with the RU Allocation field set to the maximum overlapped bandwidth of 320 MHz. Upon receiving the MU-RTS TXS TF with DYN_BANDWIDTH_IN_NON_HT set to dynamic, CAP can transmit a CTS frame to P160, excluding S160, which is busy. Similarly, in the example of the right diagram of FIG. 22, if a MU-RTS TXS TF with DYN_BANDWIDTH_IN_NON_HT set to dynamic is transmitted to the maximum overlapped bandwidth of the two APs of 160 MHz, CAP can transmit a CTS frame to P80, excluding S80, which is busy, and use the time / TXOP allocated from SAP.

[0250] If the MU-RTS Trigger frame has a bandwidth signaling TA as proposed / implemented in this specification, the CH_BANDWIDTH_IN_NON_HT parameter may also exist. CH_BANDWIDTH_IN_NON_HT may basically include the bandwidth value of the corresponding PPDU.

[0251] This specification proposes a Co-TDMA operation using a bandwidth signaling TA. Specifically, the MU-RTS TXS TF transmitted to the CAP for time allocation may have a bandwidth signaling TA, from which the value of DYN_BANDWIDTH_IN_NON_HT may be set dynamically. This allows for more successful exchanges of MU-RTS TXS TF / CTS frames, thereby reducing Co-TDMA failures and increasing media utilization.

[0252] FIG. 23 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0253] An example of FIG. 23 can be performed on a transmitting STA or a transmitting device (AP and / or non-AP STA).

[0254] Some of the steps of each example in FIG. 23 (or detailed sub-steps described later) may be omitted or changed.

[0255] Through step S2310, the transmitting device (transmitting STA) can obtain information regarding the above-described Tone Plan. As described above, the information regarding the Tone Plan includes the size and location of the RU, control information related to the RU, information regarding the frequency band in which the RU is included, information regarding the STA receiving the RU, etc.

[0256] Through step S2320, the transmitting device can construct / generate a PPDU based on acquired control information. The step of constructing / generating the PPDU may include the step of constructing / generating each field of the PPDU. That is, step S2320 includes the step of constructing an EHT-SIG field containing control information regarding a Tone Plan. That is, step S2320 may include the step of constructing a field containing control information (e.g., N bitmap) indicating the size / location of the RU and / or the step of constructing a field containing an identifier (e.g., AID) of the STA receiving the RU.

[0257] Additionally, step S2320 may include the step of generating an STF / LTF sequence transmitted through a specific RU. The STF / LTF sequence may be generated based on a pre-configured STF generation sequence / LTF generation sequence.

[0258] Additionally, step S2320 may include a step of generating a data field (i.e., MPDU) transmitted through a specific RU.

[0259] The transmitting device can transmit the PPDU configured through step S2320 to the receiving device based on step S2330.

[0260] While performing step S2330, the transmitting device may perform at least one of the following operations: CSD, Spatial Mapping, IDFT / IFFT operation, GI insertion, etc.

[0261] A signal / field / sequence configured according to the present specification can be transmitted in the form of FIG. 5.

[0262] FIG. 24 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0263] The above-described PPDU can be received according to an example of FIG. 24.

[0264] An example of FIG. 24 can be performed on a receiving STA or a receiving device (AP and / or non-AP STA).

[0265] Some of the steps (or detailed sub-steps described later) of each example in FIG. 24 may be omitted.

[0266] A receiving device (receiving STA) can receive all or part of the PPDU through step S2410. The received signal may be in the form of FIG. 5.

[0267] The sub-step of step S2410 can be determined based on step S2330 of FIG. 23. That is, step S2410 can perform an operation to restore the results of the CSD, Spatial Mapping, IDFT / IFFT operation, and GI insert operation applied in step S2330.

[0268] In step S2420, the receiving device can perform decoding of all or part of the PPDU. Additionally, the receiving device can obtain control information related to the Tone Plan (i.e., RU) from the decoded PPDU.

[0269] More specifically, the receiving device can decode the L-SIG and EHT-SIG of the PPDU based on the Legacy STF / LTF and obtain information contained in the L-SIG and EHT-SIG fields. Information regarding various Tone Plans (i.e., RU) described in this specification may be included in the EHT-SIG, and the receiving STA can obtain information regarding the Tone Plan (i.e., RU) through the EHT-SIG.

[0270] In step S2430, the receiving device can decode the remainder of the PPDU based on information regarding the Tone Plan (i.e., RU) obtained through step S2420. For example, the receiving STA can decode the STF / LTF fields of the PPDU based on information regarding the one Plan (i.e., RU). Additionally, the receiving STA can decode the data fields of the PPDU based on information regarding the Tone Plan (i.e., RU) and obtain the MPDU contained in the data fields.

[0271] Additionally, the receiving device can perform a processing operation to transmit the decoded data through step S2430 to an upper layer (e.g., MAC layer). Furthermore, if the generation of a signal is instructed from the upper layer to the PHY layer in response to the data transmitted to the upper layer, a subsequent operation can be performed.

[0272] Hereinafter, the above-described embodiment will be explained with reference to FIGS. 1 to 24.

[0273] FIG. 25 is a flowchart illustrating a procedure for transmitting a CTS frame in response to a MU-RTS TXS trigger frame in a Co-TDMA operation having a bandwidth signaling TA according to the present embodiment.

[0274] An example of FIG. 25 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0275] An example of FIG. 25 can be performed at a second AP. The first AP may be a MAPC requesting AP that initiates MAPC negotiation with the second AP regarding at least one MAPC technique. The second AP may be a MAPC responding AP that responds to the MAPC requesting AP. Additionally, the first and second APs may be set as a coordinating AP or a coordinated AP through the MAPC negotiation.

[0276] The present embodiment proposes a method for performing Co-TDMA operation by transmitting a MU-RTS TXS trigger frame using bandwidth signaling TA and receiving a CTS frame on an IDLE channel excluding a BUSY channel. Specifically, the present embodiment proposes a method for adjusting the operating bandwidth of the CTS frame to the remaining IDLE channel by setting DYN_BANDWIDTH_IN_NON_HT to dynamic, even if some of the channels indicated in the RU allocation field of the MU-RTS TXS trigger frame are BUSY. This has the effect of increasing the success rate of switching between the MU-RTS TXS trigger frame and the CTS frame, thereby reducing failures in Co-TDMA operation and increasing media utilization.

[0277] In step S2510, the second AP (access point) receives a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame from the first AP.

[0278] In step S2520, the second AP transmits a CTS (Clear To Send) frame to the first AP.

[0279] The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP. The second AP is a coordinated AP that participates in the MAPC transmission.

[0280] The above MAPC transmission may be a Co-TDMA (Coordinated Time Division Multiple Access) transmission or procedure. The above Co-TDMA transmission or procedure may be a mechanism in which one AP (Co-TDMA coordinating AP) sequentially allocates a portion of the TXOPs it has acquired to one or more other APs (Co-TDMA coordinated APs) on a time-by-time basis, so that each AP can independently perform PPDU exchanges during the corresponding time. In this case, the first AP may be a Co-TDMA coordinating AP, and the second AP may be a Co-TDMA coordinated AP.

[0281] The above Co-TDMA transmission or procedure may be performed in a polling phase, a TXOP allocation phase, and a TXOP return phase.

[0282] A TXOP for MAPC transmission may be allocated to the second AP based on the above MU-RTS TXS trigger frame. That is, the above MU-RTS TXS trigger frame may be used for Co-TDMA-based TXOP sharing in the TXOP allocation step. At this time, the TXOP allocated to the second AP may be a part of the TXOP acquired by the first AP.

[0283] The above MU-RTS TXS trigger frame includes a first and a second parameter. The first parameter is related to the transmission bandwidth of the MU-RTS TXS trigger frame. The second parameter is related to the dynamic bandwidth of the CTS frame.

[0284] Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the above channels from the above transmission bandwidth.

[0285] The MAC header of the above MU-RTS TXS trigger frame may include a TA (Transmitter Address) field.

[0286] The above TA field may be set (or reinterpreted) as a bandwidth signaling TA rather than a MAC address identifying the first AP. The bandwidth signaling TA may indicate that the MU-RTS TXS trigger frame conveys the first and second parameters.

[0287] The above MU-RTS TXS trigger frame may further include a RU (Resource Unit) allocation field.

[0288] The above RU allocation field may include allocation information for a channel where the transmission bandwidth of the MU-RTS TXS trigger frame and the transmission bandwidth of the CTS frame overlap.

[0289] The above CTS frame can be received through the remaining channel that is IDLE among the overlapping channels based on the above second parameter.

[0290] For example, based on the fact that the overlapping channel is a 320 MHz channel and the BUSY part of the channel is a secondary 160 MHz channel, the CTS frame can be received through an IDLE primary 160 MHz channel. Based on the fact that the overlapping channel is a 160 MHz channel and the BUSY part of the channel is a secondary 80 MHz channel, the CTS frame can be received through an IDLE primary 80 MHz channel.

[0291] The first parameter above may be a CH_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter. The second parameter above may be a DYN_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter.

[0292] According to the present embodiment, by using a MU-RTS TXS trigger frame including a bandwidth signaling TA, the bandwidth for receiving CTS frames from APs participating in Co-TDMA operation can be flexibly controlled at the physical layer level. In particular, even when some of the channels indicated by the RU allocation field of the MU-RTS TXS trigger frame are in a BUSY state due to interference, collision, or external BSS, by setting the DYN_BANDWIDTH_IN_NON_HT parameter to dynamic, the Co-TDMA coordinated AP can automatically exclude the BUSY channels and reconfigure the operating bandwidth to transmit CTS frames using only the IDLE channels.

[0293] As a result, unlike conventional methods that require a CTS response with a fixed bandwidth, CTS frame exchange can be continuously maintained without interruption even in environments where some subchannels are occupied, which provides the effect of substantially improving the handshake success rate between MU-RTS TXS trigger frames and CTS frames.

[0294] In addition, as situations where Co-TDMA reservations are invalidated or TXOP sharing is canceled due to CTS frame reception failure are reduced, the stability of Co-TDMA operation is improved in high-density wireless LAN environments where multiple APs coexist, and unnecessary retries and control overhead are reduced. Consequently, wireless resources consumed for control frame switching are reduced, and time and frequency resources available for actual data transmission are increased, providing the effect of simultaneously improving medium utilization and overall system throughput.

[0295] Furthermore, since the present embodiment dynamically adjusts the operating bandwidth at the PHY layer using bandwidth signaling TA and DYN_BANDWIDTH_IN_NON_HT, it can adapt to channel occupancy conditions in real time without separate upper-layer signal exchange. Accordingly, Co-TDMA-based multi-AP cooperative transmission can be performed more robustly, and technical effects can be achieved in which the reliability and efficiency of TXOP sharing are significantly improved, especially in EHT / UHR-based broadband (e.g., 160 MHz, 320 MHz) environments where partial channel occupancy or frequency fragmentation exists.

[0296] Based on the above MU-RTS TXS trigger frame, a TXOP for the MAPC transmission may be assigned to the second AP. After transmitting the CTS frame, the second AP may perform frame exchange with a non-AP STA (station) during the TXOP for the MAPC transmission. At this time, the non-AP STA may be a non-AP STA associated with the second AP.

[0297] Prior to the frame exchange sequence for the above MAPC transmission, a negotiation procedure for MAPC consensus may be performed.

[0298] Specifically, the first AP may transmit a negotiation request frame to the second AP. The first AP may receive a negotiation response frame from the second AP. The first AP may form an MAPC agreement with the second AP regarding the MAPC transmission. (Alternatively, the second AP may receive a negotiation request frame from the first AP. The second AP may receive a negotiation response frame from the first AP. The second AP may form an MAPC agreement with the first AP regarding the MAPC transmission.)

[0299] At this time, the first AP may be a MAPC requesting AP that initiates negotiations for the MAPC agreement. The second AP may be a MAPC responding AP that responds to the MAPC requesting AP.

[0300] Based on the formation of a MAPC agreement for the above Co-TDMA transmission, the first and second APs can perform the above Co-TDMA transmission or procedure.

[0301] For example, in the polling phase, the first AP may transmit an Initial Control Frame (ICF) for polling to the second AP. The first AP may receive an Initial Control Response (ICR) for the ICF from the second AP. (Alternatively, the second AP may receive an Initial Control Frame (ICF) for polling from the first AP. The second AP may transmit an Initial Control Response (ICR) for the ICF to the first AP.) In this case, the ICR may include a TXOP Sharing Solicited field.

[0302] The above MU-RTS TXS trigger frame may be transmitted based on the TXOP Sharing Solicited field being 1. When the TXOP Sharing Solicited field is set to 1, the first AP that receives the ICR can recognize that the second AP is requesting to be allocated time in this TXOP. When the TXOP Sharing Solicited field is set to 0, the first AP that receives the ICR can recognize that the second AP is not requesting to be allocated time in this TXOP.

[0303] The TXS Mode field of the above MU-RTS TXS trigger frame can be set to 2. Accordingly, the above MU-RTS TXS trigger frame can allocate time to the second AP as part of the Co-TDMA procedure. The second AP can exchange one or more MPDUs (MAC Protocol Data Units) during the allocated time through the above MU-RTS TXS trigger frame.

[0304] FIG. 26 is a flowchart illustrating the procedure for receiving a CTS frame in response to a MU-RTS TXS trigger frame in a Co-TDMA operation having a bandwidth signaling TA according to the present embodiment.

[0305] An example of FIG. 26 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0306] An example of FIG. 26 can be performed at a first AP. The first AP may be a MAPC requesting AP that initiates MAPC negotiation with the second AP regarding at least one MAPC technique. The second AP may be a MAPC responding AP that responds to the MAPC requesting AP. Additionally, the first and second APs may be established as a coordinating AP or a coordinated AP through the MAPC negotiation.

[0307] The present embodiment proposes a method for performing Co-TDMA operation by transmitting a MU-RTS TXS trigger frame using bandwidth signaling TA and receiving a CTS frame on an IDLE channel excluding a BUSY channel. Specifically, the present embodiment proposes a method for adjusting the operating bandwidth of the CTS frame to the remaining IDLE channel by setting DYN_BANDWIDTH_IN_NON_HT to dynamic, even if some of the channels indicated in the RU allocation field of the MU-RTS TXS trigger frame are BUSY. This has the effect of increasing the success rate of switching between the MU-RTS TXS trigger frame and the CTS frame, thereby reducing failures in Co-TDMA operation and increasing media utilization.

[0308] In step S2610, the first AP (access point) sends a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to the second AP.

[0309] In step S2620, the first AP receives a CTS (Clear To Send) frame from the second AP.

[0310] The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP. The second AP is a coordinated AP that participates in the MAPC transmission.

[0311] The above MAPC transmission may be a Co-TDMA (Coordinated Time Division Multiple Access) transmission or procedure. The above Co-TDMA transmission or procedure may be a mechanism in which one AP (Co-TDMA coordinating AP) sequentially allocates a portion of the TXOPs it has acquired to one or more other APs (Co-TDMA coordinated APs) on a time-by-time basis, so that each AP can independently perform PPDU exchanges during the corresponding time. In this case, the first AP may be a Co-TDMA coordinating AP, and the second AP may be a Co-TDMA coordinated AP.

[0312] The above Co-TDMA transmission or procedure may be performed in a polling phase, a TXOP allocation phase, and a TXOP return phase.

[0313] A TXOP for MAPC transmission may be allocated to the second AP based on the above MU-RTS TXS trigger frame. That is, the above MU-RTS TXS trigger frame may be used for Co-TDMA-based TXOP sharing in the TXOP allocation step. At this time, the TXOP allocated to the second AP may be a part of the TXOP acquired by the first AP.

[0314] The above MU-RTS TXS trigger frame includes a first and a second parameter. The first parameter is related to the transmission bandwidth of the MU-RTS TXS trigger frame. The second parameter is related to the dynamic bandwidth of the CTS frame.

[0315] Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the above channels from the above transmission bandwidth.

[0316] The MAC header of the above MU-RTS TXS trigger frame may include a TA (Transmitter Address) field.

[0317] The above TA field may be set (or reinterpreted) as a bandwidth signaling TA rather than a MAC address identifying the first AP. The bandwidth signaling TA may indicate that the MU-RTS TXS trigger frame conveys the first and second parameters.

[0318] The above MU-RTS TXS trigger frame may further include a RU (Resource Unit) allocation field.

[0319] The above RU allocation field may include allocation information for a channel where the transmission bandwidth of the MU-RTS TXS trigger frame and the transmission bandwidth of the CTS frame overlap.

[0320] The above CTS frame can be received through the remaining channel that is IDLE among the overlapping channels based on the above second parameter.

[0321] For example, based on the fact that the overlapping channel is a 320 MHz channel and the BUSY part of the channel is a secondary 160 MHz channel, the CTS frame can be received through an IDLE primary 160 MHz channel. Based on the fact that the overlapping channel is a 160 MHz channel and the BUSY part of the channel is a secondary 80 MHz channel, the CTS frame can be received through an IDLE primary 80 MHz channel.

[0322] The first parameter above may be a CH_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter. The second parameter above may be a DYN_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter.

[0323] According to the present embodiment, by using a MU-RTS TXS trigger frame including a bandwidth signaling TA, the bandwidth for receiving CTS frames from APs participating in Co-TDMA operation can be flexibly controlled at the physical layer level. In particular, even when some of the channels indicated by the RU allocation field of the MU-RTS TXS trigger frame are in a BUSY state due to interference, collision, or external BSS, by setting the DYN_BANDWIDTH_IN_NON_HT parameter to dynamic, the Co-TDMA coordinated AP can automatically exclude the BUSY channels and reconfigure the operating bandwidth to transmit CTS frames using only the IDLE channels.

[0324] As a result, unlike conventional methods that require a CTS response with a fixed bandwidth, CTS frame exchange can be continuously maintained without interruption even in environments where some subchannels are occupied, which provides the effect of substantially improving the handshake success rate between MU-RTS TXS trigger frames and CTS frames.

[0325] In addition, as situations where Co-TDMA reservations are invalidated or TXOP sharing is canceled due to CTS frame reception failure are reduced, the stability of Co-TDMA operation is improved in high-density wireless LAN environments where multiple APs coexist, and unnecessary retries and control overhead are reduced. Consequently, wireless resources consumed for control frame switching are reduced, and time and frequency resources available for actual data transmission are increased, providing the effect of simultaneously improving medium utilization and overall system throughput.

[0326] Furthermore, since the present embodiment dynamically adjusts the operating bandwidth at the PHY layer using bandwidth signaling TA and DYN_BANDWIDTH_IN_NON_HT, it can adapt to channel occupancy conditions in real time without separate upper-layer signal exchange. Accordingly, Co-TDMA-based multi-AP cooperative transmission can be performed more robustly, and technical effects can be achieved in which the reliability and efficiency of TXOP sharing are significantly improved, especially in EHT / UHR-based broadband (e.g., 160 MHz, 320 MHz) environments where partial channel occupancy or frequency fragmentation exists.

[0327] Based on the above MU-RTS TXS trigger frame, a TXOP for the MAPC transmission may be assigned to the second AP. After transmitting the CTS frame, the second AP may perform frame exchange with a non-AP STA (station) during the TXOP for the MAPC transmission. At this time, the non-AP STA may be a non-AP STA associated with the second AP.

[0328] Prior to the frame exchange sequence for the above MAPC transmission, a negotiation procedure for MAPC consensus may be performed.

[0329] Specifically, the first AP may transmit a negotiation request frame to the second AP. The first AP may receive a negotiation response frame from the second AP. The first AP may form an MAPC agreement with the second AP regarding the MAPC transmission. (Alternatively, the second AP may receive a negotiation request frame from the first AP. The second AP may receive a negotiation response frame from the first AP. The second AP may form an MAPC agreement with the first AP regarding the MAPC transmission.)

[0330] At this time, the first AP may be a MAPC requesting AP that initiates negotiations for the MAPC agreement. The second AP may be a MAPC responding AP that responds to the MAPC requesting AP.

[0331] Based on the formation of a MAPC agreement for the above Co-TDMA transmission, the first and second APs can perform the above Co-TDMA transmission or procedure.

[0332] For example, in the polling phase, the first AP may transmit an Initial Control Frame (ICF) for polling to the second AP. The first AP may receive an Initial Control Response (ICR) for the ICF from the second AP. (Alternatively, the second AP may receive an Initial Control Frame (ICF) for polling from the first AP. The second AP may transmit an Initial Control Response (ICR) for the ICF to the first AP.) In this case, the ICR may include a TXOP Sharing Solicited field.

[0333] The above MU-RTS TXS trigger frame may be transmitted based on the TXOP Sharing Solicited field being 1. When the TXOP Sharing Solicited field is set to 1, the first AP that receives the ICR can recognize that the second AP is requesting to be allocated time in this TXOP. When the TXOP Sharing Solicited field is set to 0, the first AP that receives the ICR can recognize that the second AP is not requesting to be allocated time in this TXOP.

[0334] The TXS Mode field of the above MU-RTS TXS trigger frame can be set to 2. Accordingly, the above MU-RTS TXS trigger frame can allocate time to the second AP as part of the Co-TDMA procedure. The second AP can exchange one or more MPDUs (MAC Protocol Data Units) during the allocated time through the above MU-RTS TXS trigger frame.

[0335] <Device Configuration>

[0336] The technical features of the present specification described above may be applied to various devices and methods. For example, the technical features of the present specification described above may be performed / supported through the device of FIG. 1 and / or FIG. 13. For example, the technical features of the present specification described above may be applied only to parts of FIG. 1 and / or FIG. 13. For example, the technical features of the present specification described above may 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 (610) and memory (620) of FIG. 13. For example, the device of the present specification transmits a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to a second AP (access point); and receives a CTS (Clear To Send) frame from the second AP.

[0337] The technical features of this specification may be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by this specification is at least one computer-readable medium comprising instructions based on execution by at least one processor.

[0338] The above CRM may store instructions for performing operations including the step of transmitting a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to a second AP (access point); and the step of receiving a CTS (Clear To Send) frame from the second AP. Instructions stored in the CRM of this specification may be executed by at least one processor. At least one processor associated with the CRM of this specification may be the processor (111, 121) or processing chip (114, 124) of FIG. 1, or the processor (610) of FIG. 13. Meanwhile, the CRM of this specification may be the memory (112, 122) of FIG. 1, the memory (620) of FIG. 13, or a separate external memory / storage medium / disk, etc.

[0339] The technical features of the present specification described above are applicable to various applications or business models. For example, the technical features described above may be applied for wireless communication in devices supporting Artificial Intelligence (AI).

[0340] Artificial intelligence refers to the field of researching artificial intelligence or the methodologies to create it, while machine learning refers to the field of researching methodologies to define and solve various problems addressed within the field of artificial intelligence. Machine learning is also defined as an algorithm that improves performance on a task through continuous experience.

[0341] An Artificial Neural Network (ANN) is a model used in machine learning that can refer to any model capable of problem-solving, composed of artificial neurons (nodes) that form a network through the connection of synapses. An artificial neural network can be defined by connection patterns between neurons in different layers, a learning process that updates model parameters, and an activation function that generates output values.

[0342] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may include one or more neurons, and the artificial neural network may include synapses connecting the neurons. In an artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through the synapses.

[0343] Model parameters refer to parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters, on the other hand, refer to parameters that must be set prior to training in a machine learning algorithm, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0344] The objective of training an artificial neural network can be viewed as determining model parameters that minimize the loss function. The loss function can be used as an indicator to determine optimal model parameters during the training process of an artificial neural network.

[0345] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0346] Supervised learning refers to a method of training an artificial neural network with labels provided for the training data; a label can refer to the correct answer (or result) that the neural network must infer when the training data is input. Unsupervised learning refers to a method of training an artificial neural network without labels provided for the training data. Reinforcement learning refers to a learning method in which an agent defined within an environment is trained to select an action or sequence of actions that maximizes the cumulative reward in each state.

[0347] Machine learning implemented using a Deep Neural Network (DNN) that includes multiple hidden layers among artificial neural networks is also called Deep Learning, and Deep Learning is a part of Machine Learning. Hereinafter, Machine Learning is used in a sense that includes Deep Learning.

[0348] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0349] A robot can refer to a machine that automatically processes or operates a given task based on its own capabilities. In particular, a robot that has the ability to perceive its environment, make decisions on its own, and perform actions can be called an intelligent robot.

[0350] Robots can be classified into industrial, medical, domestic, and military types depending on their purpose or field of use. Robots are equipped with drive units, including actuators or motors, to perform various physical movements, such as moving robot joints. Additionally, mobile robots include wheels, brakes, and propellers in their drive units, enabling them to drive on the ground or fly in the air.

[0351] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0352] Extended Reality is a collective term for Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). VR technology provides real-world objects or backgrounds solely as CG images, AR technology provides virtual CG images superimposed on real-world images, and MR technology is a computer graphics technology that mixes and combines virtual objects with the real world.

[0353] MR technology is similar to AR technology in that it displays real-world objects and virtual objects together. However, there is a difference in that while virtual objects in AR technology are used to complement real-world objects, virtual objects and real-world objects are used as equals in MR technology.

[0354] XR technology can be applied to HMDs (Head-Mount Displays), HUDs (Head-Up Displays), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0355] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

1. In a wireless LAN system, The first AP (access point) transmits a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to the second AP; and The above first AP includes the step of receiving a CTS (Clear To Send) frame from the above second AP, wherein The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. method.

2. In Paragraph 1, The MAC header of the above MU-RTS TXS trigger frame includes a TA (Transmitter Address) field, and The above TA field is set to a bandwidth signaling TA rather than a MAC address identifying the first AP, and The above bandwidth signaling TA indicates that the MU-RTS TXS trigger frame transmits the first and second parameters. method.

3. In Paragraph 1, The above MU-RTS TXS trigger frame further includes an RU (Resource Unit) allocation field, and The above RU allocation field includes allocation information for a channel where the transmission bandwidth of the MU-RTS TXS trigger frame and the transmission bandwidth of the CTS frame overlap, and The above CTS frame is received through the remaining channel that is IDLE among the overlapping channels based on the above second parameter. method.

4. In Paragraph 3, Based on the fact that the overlapping channel is a 320MHz channel and the BUSY part channel is a secondary 160MHz channel, the CTS frame is received through an IDLE primary 160MHz channel, and Based on the fact that the overlapping channel is a 160MHz channel and the BUSY partial channel is a secondary 80MHz channel, the CTS frame is received through the IDLE primary 80MHz channel method.

5. In Paragraph 1, The first parameter above is the CH_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter, and The second parameter above is the DYN_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter above. method.

6. In Paragraph 1, Based on the above MU-RTS TXS trigger frame, a TXOP for transmitting the MAPC is allocated to the second AP, and The second AP performs frame exchange with a non-AP STA (station) during the TXOP for the MAPC transmission, and The above non-AP STA is a non-AP STA associated with the above second AP. method.

7. In Paragraph 1, The step of the first AP transmitting a negotiation request frame to the second AP; The first AP receives a negotiation response frame from the second AP; and The above first AP further includes the step of forming a MAPC agreement with the above second AP regarding the MAPC transmission, wherein The above MAPC transmission is a Co-TDMA (Coordinated Time Division Multiple Access) transmission, and The above-mentioned first AP is a MAPC requesting AP that initiates negotiations for the above-mentioned MAPC agreement, and The above second AP is a MAPC responding AP that responds to the above MAPC request AP. method.

8. In Paragraph 9, Based on the MAPC agreement formed for the above Co-TDMA transmission, The first AP transmits an Initial Control Frame (ICF) for polling to the second AP; and The above first AP further includes the step of receiving an ICR (Initial Control Response) for the ICF from the above second AP, wherein The above ICR includes a TXOP Sharing Solicited field, and The above MU-RTS TXS trigger frame is transmitted based on the fact that the TXOP Sharing Solicited field is 1, and The TXS Mode field of the above MU-RTS TXS trigger frame is set to 2 method.

9. In a wireless LAN system, the first AP (access point) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: Transmit a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to the second AP; and Receive a CTS (Clear To Send) frame from the above second AP, The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. 1st AP.

10. In wireless LAN systems, The second AP (access point) receives a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame from the first AP; and The above second AP includes the step of transmitting a CTS (Clear To Send) frame to the above first AP, wherein The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. method.

11. In Paragraph 10, The MAC header of the above MU-RTS TXS trigger frame includes a TA (Transmitter Address) field, and The above TA field is set to a bandwidth signaling TA rather than a MAC address identifying the first AP, and The above bandwidth signaling TA indicates that the MU-RTS TXS trigger frame transmits the first and second parameters. method.

12. In Paragraph 10, The above MU-RTS TXS trigger frame further includes an RU (Resource Unit) allocation field, and The above RU allocation field includes allocation information for a channel where the transmission bandwidth of the MU-RTS TXS trigger frame and the transmission bandwidth of the CTS frame overlap, and The above CTS frame is received through the remaining channel that is IDLE among the overlapping channels based on the above second parameter. method.

13. In Paragraph 12, Based on the fact that the overlapping channel is a 320MHz channel and the BUSY part channel is a secondary 160MHz channel, the CTS frame is received through an IDLE primary 160MHz channel, and Based on the fact that the overlapping channel is a 160MHz channel and the BUSY partial channel is a secondary 80MHz channel, the CTS frame is received through the IDLE primary 80MHz channel method.

14. In Paragraph 10, The first parameter above is the CH_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter, and The second parameter above is the DYN_BANDWIDTH_IN_NON_HT parameter included in the TXVECTOR parameter above. method.

15. In Paragraph 10, Based on the above MU-RTS TXS trigger frame, a TXOP for transmitting the MAPC is allocated to the second AP, and The second AP performs frame exchange with a non-AP STA (station) during the TXOP for the MAPC transmission, and The above non-AP STA is a non-AP STA associated with the above second AP. method.

16. In Paragraph 10, The step of the second AP receiving a negotiation request frame from the first AP; The step of the second AP transmitting a negotiation response frame to the first AP; and The above second AP further includes the step of forming a MAPC agreement with the first AP regarding the MAPC transmission, wherein The above MAPC transmission is a Co-TDMA (Coordinated Time Division Multiple Access) transmission, and The above-mentioned first AP is a MAPC requesting AP that initiates negotiations for the above-mentioned MAPC agreement, and The above second AP is a MAPC responding AP that responds to the above MAPC request AP. method.

17. In Paragraph 16, Based on the MAPC agreement formed for the above Co-TDMA transmission, The second AP receives an Initial Control Frame (ICF) for polling from the first AP; and The above second AP further includes the step of transmitting an ICR (Initial Control Response) for the ICF to the above first AP, wherein The above ICR includes a TXOP Sharing Solicited field, and The above MU-RTS TXS trigger frame is transmitted based on the fact that the TXOP Sharing Solicited field is 1, and The TXS Mode field of the above MU-RTS TXS trigger frame is set to 2 method.

18. In a wireless LAN system, the second AP (access point) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: Receive a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame from the 1st AP; and Transmit a CTS (Clear To Send) frame to the above-mentioned first AP, The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. 2nd AP.

19. At least one computer-readable medium comprising an instruction based on execution by at least one processor, A step of transmitting a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to a second AP (access point); and The method includes the step of receiving a CTS (Clear To Send) frame from the second AP, The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. Recording media.

20. In a device in a wireless LAN system, Memory; and The processor comprises the above memory and operablely coupled thereto, wherein the processor is: Transmit a MU-RTS (Multi User-Request To Send) TXS (TXOP (Transmission Opportunity) Sharing) trigger frame to the second AP (access point); and Receive a CTS (Clear To Send) frame from the above second AP, The first AP is a coordinating AP that acquires a TXOP and initiates Multi-AP coordination (MAPC) transmission with the second AP, and The above second AP is a coordinated AP participating in the above MAPC transmission, and The above MU-RTS TXS trigger frame includes first and second parameters, and The first parameter above is related to the transmission bandwidth of the MU-RTS TXS trigger frame, and The second parameter above is related to the dynamic bandwidth of the CTS frame, and Based on the fact that some channels of the above transmission bandwidth are BUSY and the second parameter is set to dynamic, the dynamic bandwidth of the CTS frame is set to the remaining channels excluding the said some channels from the transmission bandwidth. device.

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