Indication of whether to participate in multi-AP cooperation in wireless LAN system

Abstract

The present disclosure relates to an indication of whether to participate in multi-access point (AP) coordination (MAPC) in a wireless LAN system. According to embodiments of the present disclosure, a method carried out by a first AP in a wireless LAN system comprises the steps of: establishing an agreement for MAPC with one or more other APs; receiving, from a second AP among the one or more other APs, an initial control frame (ICF) for checking whether to participate in an MAPC operation; and transmitting, to the second AP, an initial control response frame (ICR) for the ICF, wherein a Control Information field within a buffer status report (BSR) Control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

Description

Instruction on whether to participate in multi-AP cooperation in a wireless LAN system

[0001] This disclosure relates to an indication of whether to participate in multi-AP coordination (MAPC) in a wireless LAN system.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability during signal transmission to STAs, and to achieve this, various technologies are being considered to support high throughput, low latency, and extended range. For example, Multi-AP Coordination (MAPC) is known as a technology designed to improve the performance of wireless LAN systems by jointly performing tasks such as transmission scheduling, channel resource management, and interference management among multiple APs. To this end, each AP needs to exchange schedule information based on cooperation with neighboring APs or coordinate its operations based on the feasibility of cooperation. Therefore, it is necessary for an AP to instruct or report to other APs whether they will participate in the cooperation process.

[0003] The present disclosure provides a method and apparatus for indicating whether to participate in MAPC in a wireless LAN system.

[0004] According to an embodiment of the present disclosure, a method performed by a first access point (AP) in a wireless LAN system comprises: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; receiving an initial control frame (ICF) from a second AP among the one or more other APs to determine whether to participate in the MAPC operation; and transmitting an initial control response frame (ICR) for the ICF to the second AP, wherein a control information field within a buffer status report (BSR) control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

[0005] According to an embodiment of the present disclosure, a method performed by a second access point (AP) in a wireless LAN system comprises: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; transmitting an initial control frame (ICF) to a first AP among the one or more other APs to determine whether to participate in the MAPC operation; and receiving an initial control response frame (ICR) for the ICF from the first AP, wherein a control information field within a buffer status report (BSR) control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

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

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

[0008] For example, by having the first AP report its participation in the MAPC to the second AP, the second AP can quickly identify the set of APs for the cooperation trigger, thereby minimizing the cooperation trigger delay. Additionally, since cooperative operations such as scheduling, beamforming, and interference management are performed based on the APs that have indicated their participation in the MAPC, unnecessary control signal exchanges can be reduced, and cooperation efficiency can be improved.

[0009] Furthermore, by clearly identifying participation in MAPC, role sharing and resource allocation among APs can be performed more accurately, resulting in improved network throughput, reduced latency, and the stable securing of multi-AP-based transmission performance.

[0010] The advantageous effects obtainable through specific embodiments of the present disclosure are not limited to those listed above. For example, there may be various technical effects that a person skilled in the art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein and may include various effects that can be understood or derived from the technical features of the present disclosure.

[0011] FIG. 1 shows an example of a transmitting device and / or receiving device of the present disclosure.

[0012] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0013] Figure 3 is a diagram illustrating a general link setup process.

[0014] Figure 4 illustrates an example of a multi-link (ML).

[0015] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0016] FIG. 6 illustrates an example of a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present disclosure.

[0017] Figure 7 shows the operation according to UL-MU.

[0018] Figure 8 shows an example of a MAC frame header.

[0019] Figure 9 shows a trigger frame format. The trigger frame format can also be referred to as the structure of the trigger frame.

[0020] Figure 10 shows an example of the user information field format of MU-RTS TXS TF.

[0021] Figure 11 shows an example of a MAPC operation procedure including a MAPC search phase and a MAPC Agreement negotiation phase.

[0022] Figure 12 shows an example of a MAPC operation procedure including multiple AP selection steps.

[0023] Figure 13 shows an example of a Co-TDMA procedure.

[0024] FIG. 14 shows an example of a method performed by the first AP to indicate whether to participate in MAPC.

[0025] Figure 15 shows an example of a method performed by the second AP to verify participation in MAPC.

[0026] Figure 16 shows an example of a procedure for reporting participation in MAPC based on a new signaling field.

[0027] Figure 17 shows an example of a procedure for reporting participation in MAPC operations by setting existing field(s) to specific values.

[0028] In the present disclosure, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in the present disclosure, “A or B” may be interpreted as “A and / or B.” For example, in the present disclosure, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0029] A slash ( / ) or a comma used in the present disclosure may mean “and / or.” For example, “A / B” may mean “A 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.”

[0030] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0031] Additionally, parentheses used in this disclosure 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 disclosure 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.”

[0032] Additionally, “a / an” as used in this disclosure may mean “at least one” or “one or more.” Also, terms ending in “(s)” may mean “at least one” or “one or more.”

[0033] Additionally, the expressions “based on,” “on the basis of,” or “according to” as used in this disclosure mean “based at least in part on,” and do not mean “based only on one.”

[0034] Technical features described individually within one drawing in this disclosure may be implemented individually or simultaneously.

[0035] The following examples of the present disclosure may be applied to various wireless communication systems. For example, the following examples of the present disclosure may be applied to wireless local area network (WLAN) systems. For example, the present disclosure may be applied to IEEE 802.11a / g / n / ac / ax / be / bn standards. Additionally, the examples of the present disclosure may be applied to Ultra High Reliability (UHR) standards or next-generation wireless LAN standards that enhance IEEE 802.11bn. Furthermore, the examples of the present disclosure 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.

[0036] To explain the technical features of the present disclosure, the technical features to which the present disclosure can be applied are described below.

[0037] FIG. 1 shows an example of a transmitting device and / or receiving device of the present disclosure.

[0038] An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of the present disclosure may also be referred to by various names such as 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 the present disclosure 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 the present disclosure may also be referred to by various names such as receiving apparatus, transmitting device, receiving STA, transmitting STA, receiving device, transmitting device, etc.

[0039] 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 the present disclosure can perform the functions of an AP and / or a non-AP. In the present disclosure, an AP may also be indicated as an AP STA.

[0040] The STA (110, 120) of the present disclosure 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 the present disclosure may be implemented in various devices such as mobile phones, vehicles, and personal computers. Furthermore, the STA of the present disclosure may support communication for various communication services such as voice calls, video calls, data communication, and self-driving.

[0041] In the present disclosure, the STA (110, 120) may include a medium access control (MAC) that complies with the specifications of the IEEE 802.11 standard and a physical layer interface for the wireless medium.

[0042] Based on side drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0043] 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.

[0044] 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.).

[0045] 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).

[0046] 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.).

[0047] 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).

[0048] 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).

[0049] 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).

[0050] 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., PPPDU) may be performed by the transceiver (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 processor (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.

[0051] The device / STA of the aforementioned supplementary drawing (a) of FIG. 1 can be modified as shown in supplementary drawing (b) of FIG. 1. Below, the STA (110, 120) of the present disclosure will be described based on supplementary drawing (b) of FIG. 1.

[0052] 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 the memory (112, 122) shown in side drawing (b) of FIG. 1 can perform the same function as the processor (111, 121) and the memory (112, 122) shown in side drawing (a) of FIG. 1 described above.

[0053] 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 disclosure 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).

[0054] 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 transceiver (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 transceiver (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 transceiver (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.

[0055] 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.

[0056] 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 EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or a processor enhanced therefrom.

[0057] In the present disclosure, 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 the present disclosure, 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.

[0058] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0059] The top of Figure 2 shows the structure of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 infrastructure BSS (basic service set).

[0060] 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).

[0061] 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.

[0062] 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).

[0063] 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).

[0064] 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).

[0065] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0066] 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.

[0067] Figure 3 is a diagram illustrating a general link setup process.

[0068] 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.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Figure 4 illustrates an example of a multi-link (ML).

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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).

[0081] The specific features of the present disclosure are not limited to the specific features of FIG. 4. That is, the number of links can be defined in various ways, and a plurality of links can be defined in various ways within at least one band.

[0082] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0083] The device illustrated in FIGS. 1 to 4 (e.g., AP STA, non-AP STA) can be modified as in FIG. 5. The transceiver (530) of FIG. 5 may be identical to the transceiver (113, 123) of FIG. 1. The transceiver (530) of FIG. 5 may include a receiver and a transmitter.

[0084] The processor (510) of FIG. 5 may be the same as the processor (111, 121) of FIG. 1. Alternatively, the processor (510) of FIG. 5 may be the same as the processing chip (114, 124) of FIG. 1.

[0085] The memory (150) of FIG. 5 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (150) of FIG. 5 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0086] Referring to FIG. 5, a power management module (511) manages power for a processor (510) and / or a transceiver (530). A battery (512) supplies power to the power management module (511). A display (513) outputs results processed by the processor (510). A keypad (514) receives input to be used by the processor (510). The keypad (514) may be displayed on the display (513). A SIM card (515) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and associated keys used to identify and authenticate a subscriber in a mobile device such as a mobile phone and a computer.

[0087] Referring to FIG. 5, the speaker (540) can output sound-related results processed by the processor (510). The microphone (541) can receive sound-related inputs to be used by the processor (510).

[0088] FIG. 6 illustrates an example of a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present disclosure.

[0089] The STA of the present disclosure (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) can transmit and / or receive the PPDU of FIG. 6. The PPDU described in the present disclosure may have the structure of FIG. 6, for example. Additionally, the PPDU described in the present disclosure may be referred to by various names such as Ultra High Reliability (UHR) PPDU, Transmit PPDU, Receive PPDU, Type 1, or Type N PPDU. The PPDU described in the present disclosure may be used in WLAN systems defined according to IEEE 802.11bn and / or next-generation WLAN systems that improve upon IEEE 802.11bn.

[0090] The PPDU of FIG. 6 may be related to various PPDU types used in UHR systems. For example, the example of FIG. 6 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. 6 is related to NDP, the illustrated Data field may be omitted. If the PPDU of FIG. 6 is used for TB (Trigger-based) mode, the UHR-SIG of FIG. 6 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. 6.

[0091] In FIG. 6, 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).

[0092] Each block illustrated in FIG. 6 may be referred to as a field / subfield / signal, etc. As illustrated in FIG. 6, 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.

[0093] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in Fig. 6 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.

[0094] The PPDU of Fig. 6, 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).

[0095] The L-SIG field of FIG. 6 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.

[0096] 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}.

[0097] 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.

[0098] After the RL-SIG in Fig. 6, 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.

[0099] 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.

[0100] 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.

[0101] 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".

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] For example, U-SIG may include: 1) a bandwidth field containing information regarding bandwidth; 2) a field containing information regarding the Modulation and Coding Scheme (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.

[0109] Preamble puncturing may be applied to the PPDU of Fig. 6. 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.

[0110] 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.

[0111] 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.

[0112] 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).

[0113] 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).

[0114] 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.

[0115] The UHR-SIG of FIG. 6 may include control information for a receiving STA. The UHR-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0116] 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).

[0117] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 6 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 the present disclosure can be transmitted / received through a RU (resource unit) defined by a plurality of subcarriers / tones.

[0118] FIG. 7 illustrates the operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can acquire a TXOP (725) by performing channel access through contending (i.e., Backoff operation) and transmit a Trigger frame (730). That is, the transmitting STA (e.g., AP) can transmit a PPDU containing the Trigger frame (730). When the PPDU containing the Trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0119] TB PPDUs (741, 742) are transmitted at the same time and may be transmitted from multiple STAs (e.g., User STAs) with an AID indicated within a Trigger frame (730). An ACK frame (750) for a TB PPDU may be implemented in various forms. For example, an ACK frame (750) for a TB PPDU may be implemented in the form of a BA (block ACK).

[0120] In FIG. 7, the transmission(s) of the Trigger Frame (730), TB PPDU (741, 742) and / or ACK Frame (750) can be performed within TXOP (725).

[0121] The structure and types / subtypes of MAC frames are described below.

[0122] Figure 8 shows an example of a MAC frame header.

[0123] As illustrated, the MAC frame may include a frame control field / information of 2 octets in length, a duration field / information of 2 octets in length, a Receiver Address (RA) field / information of 6 octets in length, and a Transmitter Address (TA) field / information of 6 octets in length. As illustrated in FIG. 8, the four fields may be consecutive with each other. The MAC header of FIG. 8 may be modified in various ways, and a new field may be inserted between the four illustrated fields, or at least one of the illustrated fields may be omitted.

[0124] The MAC header shown in FIG. 8 may be located at the very beginning of the MAC frame. That is, the MAC frame may include a MAC header such as that shown in FIG. 8 and a MAC body field / information following the MAC header. The MAC frame containing the MAC header of FIG. 8 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) shown in FIG. 5.

[0125] MAC frames included in the data fields of the PPDU of the present disclosure can be classified into various types. For example, MAC frames of the present disclosure can be classified into control frames, management frames, and data frames.

[0126] For example, a management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames / signals defined in conventional WLANs. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 8 are set to 00. Additionally, the values ​​of the subtype fields (B7, B6, B5, B4) in FIG. 8 are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

[0127] For example, the control frame includes the Trigger Beamforming Report Poll, NDP Announcement (NDPA), Control Frame Extension, Control Wrapper, Block Ack Request (BlockAckReq), Block Ack (BlockAck), PS-Poll, RTS, CTS, Ack, and CF-End frames / signals defined in conventional WLANs. For the control frame, the values ​​of the type fields (B3 and B2) in FIG. 8 are set to 01. Also, the values ​​of the subtype fields (B7, B6, B5, B4) in FIG. 8 are as follows: Trigger(0010), Beamforming Report Poll(0100), NDP Announcement(0101), Control Frame Extension(0110), Control Wrapper(0111), BlockAckReq(1000), BlockAck(1001), PS-Poll(1010), RTS(1011), CTS(1100), Ack(1101), CF-End(1110).

[0128] For example, the data frame includes (QoS) Data, (QoS) Null, etc., defined in conventional WLANs. For the management frame, the value of the type field (B3 and B2) in Fig. 8 is set to 10.

[0129] The MAC header of a MAC frame (e.g., control frame, management frame, data frame) may include an HT Control field, and the HT Control field may include an aggregated-control (A-Control) subfield. For example, the HT Control field may consist of 32 bits B0 through B31, and the A-Control subfield may consist of B2 through B31 of the HT Control field where B0 and B1 are set to 1 (i.e., an HE variant HT Control field). That is, the A-Control subfield may be 30 bits of information.

[0130] A 30-bit A-Control subfield can have a structure as shown in below:

[0131] Control ListPadding

[0132] The bit size (or number of bits) of the Control List subfield can be variable. The bit size of the padding can be zero or greater. A Control List can contain one or more Control subfields. Each Control subfield can have a structure as shown in below:

[0133] Control IDControl Information

[0134] The bit size of the Control ID subfield can be 4 (e.g., B0 through B3). The bit size of Control Information can be variable. The values ​​of the Control ID subfield can be defined as shown in below:

[0135] Control ID valueMeaningLength of the Control Information subfield (bits)0Triggered response scheduling (TRS)261Operating mode (OM)122HE link adaptation (HLA) / EHT link adaptation (ELA)263Buffer status report (BSR)264UL power headroom (UPH)85Bandwidth query report (BQR)106Command and status (CAS)87EHT operating mode (EHT) OM)68Single response scheduling (SRS)109AP assistance request (AAR)2010Multi-link power management (MLPM)2011Enhanced buffer status report (EBSR)1412-14Reserved-15Ones need expansion surely (ONES)26

[0136] For example, a Control subfield with a Control ID subfield value set to 3 may be a BSR Control subfield. The Control Information subfield of the BSR Control subfield contains buffer status information used for UL MU operation. The format of the BSR Control subfield is shown in below.

[0137] ACI BitmapDelta TIDACI HighScaling FactorQueue Size HighQueue Size All

[0138] The ACI Bitmap subfield is 4 bits (B0–B3). The Delta TID subfield is 2 bits (B4–B5). The ACI High subfield is 2 bits (B6–B7). The Scaling Factor subfield is 2 bits (B8–B9). The Queue Size High subfield is 8 bits (B10–B17). The Queue Size All subfield is 8 bits (B18–B25). The ACI Bitmap subfield indicates the access category (AC) in which the buffer status is reported, and the corresponding encoding is shown in below.

[0139] B0B1B2B3AC_BE(best effort)AC_BK(background)AC_VI(video)AC_VO(voice)

[0140] Each bit of the ACI Bitmap subfield is set to 1 to indicate that the buffer state of the corresponding AC is included in the Queue Size All subfield, and to 0 otherwise. However, if the ACI Bitmap subfield is 0 and the Delta TID subfield is 3, the buffer state of all 8 TIDs is included. The Delta TID subfield indicates the number of TIDs for which the STA reports the buffer state, together with the value of the ACI Bitmap subfield.

[0141] The ACI High subfield indicates the ACI of the AC for which BSR is specified in the Queue Size All subfield. The mapping between ACI and AC is shown in below.

[0142] ACIAC0AC_BE1AC_BK2AC_VI3AC_VO

[0143] STAs that are not APs reporting buffer status determine which queues should be given higher priority compared to other queues. This decision can be based on factors such as traffic waiting time, QoS latency requirements, and the amount of buffered traffic. The Scaling Factor subfield indicates the SF of the Queue Size High and Queue Size All subfields in octets. The encoding of the Scaling Factor subfield is shown in below.

[0144] Scaling Factor subfieldScaling factor,SF(octets)016125622048332768

[0145] The Queue Size High subfield indicates the amount of buffered traffic in SF octets for the AC identified by the ACI High subfield. This AC targets the STA identified by the receiver address of the frame containing the BSR Control subfield. The Queue Size All subfield indicates the amount of buffered traffic in SF octets for all ACs identified by the ACI Bitmap subfield. This AC targets the STA identified by the receiver address of the frame containing the BSR Control subfield.

[0146] The Queue Size values ​​in the Queue Size High and Queue Size All subfields are the total size of all MSDUs and A-MSDUs buffered in the STA (including MSDUs or A-MSDUs in the same PSDU as the frame containing the BSR Control subfield) rounded to a multiple of the nearest SF octet. These values ​​are stored in the forwarding queues used for MSDUs and A-MSDUs with the AC specified in the ACI High and ACI Bitmap subfields, respectively. The Queue Size is based on the data received by the STA in the MAC SAP (MA-UNITDATA.request). Data of a higher tier than the MAC is not considered.

[0147] Buffered MSDU is data received from MA-UNITDATA.request that was not successfully transmitted and was not discarded.

[0148] If the Queue Size value in the Queue Size High and Queue Size All subfields is 254, it indicates that the amount of buffered traffic is greater than 254 × SF octets. If the Queue Size value in the Queue Size High and Queue Size All subfields is 255, it indicates that the amount of buffered traffic is unspecified or of unknown size.

[0149] The queue size value of a QoS data frame containing a fragment can be maintained constant across all fragments, even if the amount of traffic in the queue changes as consecutive fragments are transmitted.

[0150] The MAC frames / signals used in this disclosure can be identified through the type field / information and subtype field / information described above. For example, the “trigger frame” of this disclosure may refer to a MAC frame in which the type bits B3 and B2 within the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 within the frame control field are set to 0010. The various MAC frames described in this disclosure are inserted into / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDU).

[0151] Figure 9 shows a trigger frame format. The trigger frame format can also be referred to as the structure of the trigger frame.

[0152] Referring to FIG. 9, a trigger frame may include a frame control field, a duration / ID field, a receiver address (RA) field, a transmitter address (TA) field, a common info field, a user info list field, a padding field, and / or a frame check sequence (FCS) field. Optionally, the trigger frame may further include a special user info field between the common info field and the user info list field. The user info list field may include one or more user info fields. The frame control field, the duration / ID field, the RA field, and the TA field may constitute a MAC header.

[0153] For example, a common information field may include a trigger type subfield. The trigger type subfield value may indicate a trigger frame variant as shown in :

[0154] Trigger type subfield valueTrigger frame variant0Basic1Beamforming Report Poll (BFRP)2MU-BAR3MU-RTS4Buffer Status Report Poll (BSRP)5GCR MU-BAR6Bandwidth Query Report Poll (BQRP)7NDP Feedback Report Poll (NFRP)8Ranging9-15Reserved

[0155] For example, if the value of the trigger type subfield is set to 0, the corresponding trigger frame may be a basic trigger frame. For example, if the value of the trigger type subfield is set to 3, the corresponding trigger frame may be a multi-user (MU) RTS trigger frame. Meanwhile, according to the EHT (or 802.11be) standard, to support Peer-to-Peer (P2P) transmission to non-AP STAs, the AP may allocate a portion of the time interval within a TXOP acquired by the AP. To allocate a portion of the time interval within a TXOP, a TXOP Sharing Mode subfield may be defined within the Common Info Field of a MU-RTS trigger frame. When the value of the TXOP Sharing Mode subfield is a non-zero value, such a MU-RTS trigger frame may be referred to as a MU-RTS TXOP Sharing (TXS) Trigger frame (TF). A description of the values ​​of the TXOP Sharing Mode subfield is shown in below:

[0156] Triggered TXOP Sharing Mode subfield valueDescription0MU-RTS that does not initiate MU-RTS TXOP sharing procedure.1MU-RTS that initiates MU-RTS TXOP sharing procedure wherein a scheduledSTA can only transmit MPDU(s) addressed to its associated AP.2MU-RTS that initiates MU-RTS TXOP sharing procedure wherein a scheduled STA can transmit MPDU(s) addressed to its associated AP or addressed to another STA.3Reserved.

[0157] For example, if the value of the TXOP shared mode subfield is 1, one or more (non-TB) PPDU transmissions to the AP may be supported. If the value of the TXOP shared mode subfield is 2, P2P transmissions as well as (non-TB) PPDU transmissions to the AP may be supported. In this disclosure, the MU-RTS TXS TF may also be briefly referred to as a TXS trigger frame.

[0158] Figure 10 shows an example of the user information field format of MU-RTS TXS TF.

[0159] Referring to FIG. 10, the user information field may include an AID subfield, an RU allocation subfield, an allocation duration subfield, reserve bits and / or a PS160 subfield.

[0160] The AID subfield may indicate the AID for the STA. The RU assignment subfield may indicate the RU assignment for the STA.

[0161] The allocation period subfield can contain 9 bits from B20 to B28 in MU-RTS TXS TF and can indicate the allocation period in units of 16us. In this case, the maximum length of the allocation period that can be indicated by the allocation period subfield can be 2^9 = 8192us.

[0162] The PS160 subfield can indicate a primary 160MHz channel or a second 160MHz channel to which RU or MRU allocation applies.

[0163] Meanwhile, although a large number of APs are installed adjacent 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 related to coordination between APs in frequency, time, and spatial domains (e.g., RU selection, Joint transmission, Nulling) have been proposed, and it is necessary to address the various issues that may arise during AP coordination.

[0164] In the present disclosure, multi-AP coordination (MAPC) is proposed. MAPC may be based on techniques for reducing various interferences, such as inter-symbol interference (ISI), through coordination with neighboring APs (e.g., APs located in overlapping BSSs).

[0165] For example, MAPC can be classified into MAPC methods (or cooperative methods) based on various technologies / types / formats / protocols. For example, a cooperative method may include Co-TDMA (Coordinated TDMA), which distinguishes wireless resources allocated to multiple APs based on the time axis (time domain). Additionally or generally, a cooperative method may include C-OFDMA (Coordinated OFDMA), which distinguishes wireless resources allocated to multiple APs based on the frequency axis (time domain). Additionally or generally, a cooperative method may include Co-SR (Coordinated Spatial Reuse), which applies Spatial Reuse (SR) to at least one AP. Additionally or generally, a cooperative method may include Coordinated Beamforming (Co-BF) / nulling, which transmits by nulling interference occurring from neighbors (e.g., adjacent AP / STA, and / or OBSS AP / OBSS STA). Additionally or generally, the cooperative method 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 cooperative method 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.

[0166] In the present disclosure, operations based on MAPC may also be referred to as multiple AP operations / multiple AP transmissions / MAPC operations / MAPC transmissions. Additionally, “MAPC operations / transmissions” and “MAPC methods (or cooperative methods)” may be used interchangeably.

[0167] The Multi-AP Coordination (MAPC) framework is described below.

[0168] The MAPC framework includes various methods and procedures such as Co-BF, Co-SR, Co-TDMA, Co-RTWT, and Co-CR, and APs operating BSS on the same 20MHz basic channel cooperate to reduce interference levels and improve network performance such as media utilization efficiency, communication stability, and latency.

[0169] If an AP has established an Agreement regarding the relevant MAPC method, it may use the MAPC method with other APs.

[0170] The common procedures / steps applicable to all cooperation methods are as follows.

[0171] - MAPC Discovery Procedure / Steps: The AP advertises and discovers the MAPC functions and parameters of other APs.

[0172] - MAPC Agreement Negotiation Procedures / Steps: APs may conduct negotiation procedures for the MAPC and establish an agreement for the MAPC. Accordingly, a set of APs with established agreements for the MAPC may be formed.

[0173] - Multiple AP Selection Procedure / Step: An AP may select an AP to perform the MAPC from the set of APs configured in the MAPC Agreement Negotiation Procedure / Step.

[0174] - Cooperation Trigger Procedure / Step: An AP can trigger MAPC for the selected AP in the Multi-AP Selection Procedure / Step.

[0175] All other specific procedures for each cooperation method are described below in "II. Procedures for Specific Multi-AP Cooperation Methods".

[0176] Figure 11 shows an example of a MAPC operation procedure including a MAPC search phase and a MAPC Agreement negotiation phase.

[0177] Referring to Fig. 11, APs with MAPC capabilities can establish MAPC consensus with neighboring APs and perform MAPC operations. In order for MAPC operations to be performed between two APs, the two APs exchange (i.e., negotiate) their respective capability information and / or requirements in advance, establish consensus based on the acquired information, and perform MAPC operations based on MAPC methods (e.g., Co-TDMA, Co-BF, Co-SR). APs with MAPC capabilities can perform a search and / or negotiation / consensus process to perform MAPC with neighboring APs, thereby establishing MAPC with neighboring APs and / or configuring MAPC. Subsequently, the APs that have configured MAPC can perform MAPC based on the information agreed upon during the negotiation process (e.g., when acquiring a TXOP).

[0178] In the present disclosure, an AP that initiates and / or triggers a MAPC operation may be referred to as a Coordinating AP (or Sharing AP (SAP)), and an AP that receives a TXOP from the Coordinating AP and / or triggers a MAPC operation may be referred to as a Coordinated AP (or Shared AP (DAP) / Triggered AP / Peer AP). Such designations (names) may be changed and are not limited.

[0179] The search and negotiation / consensus process shown in Fig. 11 is a procedure that must be performed in common for various MAPC methods. Based on the negotiation procedures performed by APs with their respective neighboring AP(s), one or more cooperative APs may exist, and before a specific AP acquires a TXOP and performs an actual MAPC operation (e.g., Co-SR / BF / TDMA), a procedure to determine whether to participate in the said MAPC operation, / or a procedure to select a target AP for cooperation, and / or a procedure to notify that a specific MAPC operation is scheduled to start needs to be performed.

[0180] Figure 12 shows an example of a MAPC operation procedure including multiple AP selection steps.

[0181] Referring to FIG. 12, the Coordinating AP that has acquired the TXOP may perform a multi-AP selection procedure. The multi-AP selection procedure may include a procedure to determine whether to participate in the said MAPC operation before performing the actual MAPC operation (e.g., Co-SR / BF / TDMA), a procedure to select the target AP for cooperation, and / or a procedure to notify that a specific MAPC operation is scheduled to start, and may also be referred to as a schedule notification procedure / step, a cooperation notification procedure / step, or cooperation polling. Depending on the type of ICF (or trigger frame / poll request frame / cooperation request frame) transmitted from the Coordinating AP and / or the type of response frame solicited by said frame, the Coordinated AP may transmit an ICR (or management frame).

[0182] I. Common Procedures for All Multi-AP Cooperation Methods

[0183] 1. MAPC Discovery Procedure / Steps

[0184] In the MAPC discovery procedure / step, the AP advertises and discovers the MAPC functions and parameters of other APs.

[0185] An AP can advertise its MAPC capabilities, common MAPC parameters, and MAPC method-specific parameters by sending a MAPC Discovery Request frame to a broadcast address or to other APs as a frame individually addressed.

[0186] When an AP receives a request MAPC Discovery Request frame from a sending AP, the AP must respond by sending a MAPC Discovery Response frame to a broadcast address or by sending a management frame individually addressed to the sending AP. The Dialog Token field value of the MAPC Discovery Response frame sent by the AP must be set to be the same as the Dialog Token field value of the request MAPC Discovery Request frame.

[0187] An AP transmitting a MAPC Discovery Request frame or a MAPC Discovery Response frame may include a Per-Scheme Profile subelement for each MAPC scheme that signals a function to the reported MAPC element. The AP must not include a MAPC Scheme Request Set field in the reported Per-Scheme Profile subelement.

[0188] If an AP sending a MAPC Discovery Request frame or a MAPC Discovery Response frame to a peer AP sets the MAPC Security Supported field included in the MAPC element to 1, the AP must include the RSNE field and the RSNXE field in the Security Profile subelement of the MAPC element.

[0189] 2. MAPC Agreement Negotiation Procedures / Steps

[0190] In the MAPC Agreement negotiation process / stage, APs negotiate with each other to establish the MAPC Agreement.

[0191] A MAPC requesting AP is an AP that initiates MAPC negotiations with other APs regarding one or more MAPC schemes.

[0192] If the peer AP sets the corresponding field for support for that MAPC method in the MAPC Common Info field reported in the MAPC Discovery Request frame, MAPC Discovery Response frame, or MAPC Negotiation Request frame to 0, the MAPC requesting AP does not initiate MAPC negotiation with the peer AP for a specific MAPC method.

[0193] The MAPC response AP is the AP that responds to the MAPC request AP.

[0194] A MAPC requesting AP can initiate MAPC negotiation for one or more MAPC schemes by sending individually addressed MAPC Negotiation Request frames to other APs. The MAPC Negotiation Request frame must include a MAPC element containing one or more Per-Scheme Profile subelements in the MAPC Schemes Info field.

[0195] Additionally, if the MAPC request AP does not indicate support for the corresponding MAPC scheme in the MAPC Capabilities field included in the MAPC element, it must not include a Per-Scheme Profile subelement for that MAPC scheme in the MAPC element. If a Per-Scheme Profile subelement is included in the MAPC element, it must include a MAPC Scheme Request Set field containing one or more MAPC Scheme Request fields.

[0196] Each Per-Scheme Profile subelement in the MAPC Schemes Info field of the MAPC Negotiation Request frame conveys a request for a specific MAPC scheme.

[0197] Upon receiving an individually addressed MAPC Negotiation Request frame from the MAPC requesting AP, the MAPC responding AP must respond by sending an individually addressed MAPC Negotiation Response frame to the MAPC requesting AP. The value of the Dialog Token field in the MAPC Negotiation Response frame must be set to be identical to the value of the Dialog Token field in the MAPC Negotiation Request frame. If the MAPC responding AP accepts one or more of the requests included in the received MAPC Negotiation Request frame, the status code field is set to SUCCESS.

[0198] Otherwise, the MAPC response AP sets the appropriate rejection status code in the corresponding status field. The MAPC Negotiation Response frame must include a MAPC element containing one Per-Scheme Profile subelement in the MAPC Schemes Info field for each Per-Scheme Profile subelement included by the MAPC request AP in the MAPC Negotiation Request frame. In the MAPC Negotiation Response frame, each Per-Scheme Profile subelement must include a MAPC Scheme Request field where the MAPC Operation Type field is set to 3, 4, or 5. If the MAPC Operation Type field is set to 3 or 4, the MAPC Request Parameter Set field is not included. To accept the request, the MAPC Operation Type field must be set to 3. To reject the request, the MAPC Operation Type field must be set to 4. To reject the request and indicate that the MAPC response AP may accept subsequent requests using the same parameter values ​​included in the MAPC Request Parameter Set, the MAPC Operation Type field must be set to 5.

[0199] To request the establishment of a new Agreement, the MAPC requesting AP must set the MAPC Operation Type field to 0. If the MAPC Operation Type field is set to 0, the MAPC Request Parameter Set is included for each specific MAPC method in accordance with the rules defined in "II. Procedures for Specific Multi-AP Cooperation Methods".

[0200] If the MAPC request AP sets the corresponding field that enables the establishment of a MAPC Agreement for the corresponding MAPC method in the MAPC Discovery Request frame, MAPC Discovery Response frame, or MAPC Negotiation Request frame to 0, the MAPC response AP cannot request the establishment of a new Agreement for a specific MAPC method.

[0201] If the MAPC responding AP accepts a request to establish a new MAPC Agreement for a specific MAPC method, the MAPC requesting AP and the MAPC responding AP have established a MAPC Agreement for that specific MAPC method.

[0202] For example, when the MAPC requesting AP transmits a MAPC Negotiation Request frame containing a Co-BF profile and a Co-RTWT profile, the Co-BF profile contains a MAPC method request field for the request to establish a new agreement (MAPC Operation Type is set to 0), and the Co-RTWT profile contains three MAPC method request fields for the request to establish a new agreement. The MAPC responding AP responds with a MAPC Negotiation Response frame containing a Co-BF profile and a Co-RTWT profile. The Co-BF profile contains a MAPC method request field indicating the response to the request to establish an agreement, and the Co-RTWT profile contains three MAPC method request fields indicating the response to the establishment of the agreement. In this example, the MAPC requesting AP and the MAPC responding AP can establish up to one Co-BF Agreement and up to three Co-RTWT Agreements (one per R-TWT schedule).

[0203] The MAPC request AP and the MAPC response AP can establish up to one MAPC Agreement for Co-BF, Co-SR, and Co-TDMA, respectively, and up to one MAPC Agreement per R-TWT schedule for Co-RTWT.

[0204] 3. Multiple AP Selection Procedure / Steps

[0205] In the multi-AP selection procedure / step, an AP may perform cooperative transmission by selecting one or more other APs from the set of APs that have established a MAPC Agreement. The multi-AP selection procedure / step may include a polling step (e.g., Co-TDMA) and / or an invite step (e.g., Co-BF / Co-SR). The multi-AP selection procedure / step is also referred to as the schedule announcement procedure / step, cooperative announcement procedure / step, or cooperative polling. Further details are described in "II. Procedures for Specific Multi-AP Cooperative Methods" below.

[0206] 4. Collaboration Triggering Procedures / Steps

[0207] In the cooperative triggering procedure / step, the AP initiates cooperative transmission by sending a trigger frame to another AP, and performs cooperative transmission with that AP upon receiving a response frame for the trigger frame from that AP. Details are described below in "II. Procedure for Specific Multi-AP Cooperative Methods."

[0208] II. Procedures for Specific Multi-AP Cooperation Methods

[0209] 1. Coordinated beamforming (Co-BF)

[0210] The purpose of Coordinated Beamforming (Co-BF) is to make media usage more efficient by allowing two APs with multiple transmission chains to transmit simultaneously to non-AP STAs connected to each AP. Each AP transmits to connected non-AP STAs within its own BSS, while simultaneously minimizing interference to non-AP STAs connected to other APs by utilizing the CSI of the channel between each AP and the other AP receiving STA in the Co-BF transmission. The number of APs participating in the Co-BF transmission is two. The maximum number of spatial streams for each receiving STA in the Co-BF transmission is two. The AP must obtain the CSI required to perform the Co-BF transmission.

[0211] A Co-BF cooperative AP is an AP where dot11CoBFOptionImplemented is true, acquires a TXOP, and sends a Co-BF Invite frame to invite other APs to perform a Co-BF transmission. A Co-BF cooperative AP is an AP where dot11CoBFOptionImplemented is true, receives a Co-BF Invite frame from a Co-BF cooperative AP, and performs a Co-BF transmission. The Co-BF transmission sequence is initiated by the Co-BF cooperative AP. An STA where dot11CoBFOptionImplemented is false, or where dot11CoBFOptionImplemented is true but Co-BF behavior is disabled, is not scheduled for the Co-BF sounding sequence or Co-BF transmission sequence by the connected AP. A non-AP STA where dot11CoBFOptionImplemented is true can enable or disable Co-BF behavior. An AP must not initiate a Co-BF transmission sequence with another AP unless the two APs establish a MAPC Agreement on Co-BF according to the Co-BF negotiation procedure or other methods.

[0212] When a non-AP STA that supports Co-BF behavior (re)connects with an AP, Co-BF behavior is disabled by default. UHR non-AP STAs that support Co-BF behavior and wish to enable or disable Co-BF behavior must follow the rules regarding the frequency of sending such requests. The connected AP may accept the requests.

[0213] (1) Co-BF negotiation (i.e., MAPC Agreement negotiation procedure / steps for Co-BF)

[0214] The AP requesting the MAPC must include a Co-BF profile in the MAPC element contained in the MAPC Negotiation Request frame that initiates MAPC Agreement negotiations for the Co-BF Agreement. The Co-BF profile must include one MAPC Scheme Request field.

[0215] When the MAPC Response AP responds to the MAPC Request AP during MAPC Agreement negotiation for a Co-BF Agreement, it must include a Co-BF profile in the MAPC element contained within the MAPC Negotiation Response frame. The Co-BF profile must include one MAPC Scheme Request field.

[0216] The MAPC requesting AP must not set the MAPC Operation Type field to 1 or 2 if a Co-BF Agreement has not been established between the MAPC requesting AP and the MAPC responding AP. If a Co-BF Agreement has already been established between the MAPC requesting AP and the MAPC responding AP, the MAPC requesting AP must not set the MAPC Operation Type field to 0.

[0217] The MAPC response AP must not set the MAPC Operation Type field included in the MAPC Scheme Request field of the Co-BF profile included in the MAPC Negotiation Response frame to 5.

[0218] (2) Co-BF invitation stage (i.e., Co-BF multiple AP selection procedure / stage)

[0219] The Co-BF cooperating AP must initiate Co-BF transmission with the Co-BF cooperating AP by sending a Co-BF Invite frame to the Co-BF cooperating AP. The Co-BF Invite frame must be a BSRP NTB trigger frame. The TA field of the Co-BF Invite frame must be set to the MAC address of the Co-BF cooperating AP, and the RA field of the Co-BF Invite frame must be set to the MAC address of the Co-BF cooperating AP. The Co-BF Invite frame requests a Co-BF response frame from the Co-BF cooperating AP specified by the Co-BF Invite frame.

[0220] A Co-BF cooperative AP that receives a Co-BF Invite frame must send a Co-BF acknowledgment frame to the Co-BF cooperative AP after aSIFSTime has passed since the PPDU delivering the Co-BF Invite frame was terminated. The Co-BF acknowledgment frame must be a multi-terminal BlockAck frame. The TA field of the Co-BF acknowledgment frame must be set to the MAC address of the Co-BF cooperative AP, and the RA field of the Co-BF acknowledgment frame must be set to the MAC address of the Co-BF cooperative AP.

[0221] (3) Co-BF cooperation triggering procedure / step

[0222] The Co-BF cooperative AP must send a Co-BF trigger frame to the Co-BF cooperative AP, and then the Co-BF cooperative AP and the Co-BF cooperative AP simultaneously send data PPDUs.

[0223] 2. Coordinated spatial reuse (Co-SR)

[0224] The purpose of Coordinated Spatial Reuse (Co-SR) is to allow for more efficient use of the medium by transmitting simultaneously from multiple APs using transmission power control. The number of APs participating in Co-SR transmission is 2.

[0225] A Co-SR cooperating AP is an AP where dot11CoSROptionImplemented is true, acquires a TXOP, and initiates a Co-SR transport with another AP. A Co-SR cooperating AP is an AP where dot11CoSROptionImplemented is true, and joins the Co-SR transport initiated by the Co-SR cooperating AP. The Co-SR transport must be initiated by the Co-SR cooperating AP. An AP must not perform a Co-SR transport to a STA where dot11CoSROptionImplemented is false or where dot11CoSROptionImplemented is true but Co-SR operation is disabled. A non-AP STA where dot11CoSROptionImplemented is true can enable or disable Co-SR operation.

[0226] Unless the two APs establish a MAPC Agreement on Co-SR through Co-SR negotiation or other methods, an AP must not initiate Co-SR transmission with another AP.

[0227] When a non-AP STA that supports Co-SR operation (re)connects with an AP, Co-SR operation is disabled by default. UHR non-AP STAs that support Co-SR operation and wish to enable or disable Co-SR operation must follow the rules regarding the frequency of sending such requests. The connected AP may accept the requests.

[0228] (1) Co-SR negotiation (i.e., MAPC Agreement negotiation procedure / steps for Co-SR)

[0229] The AP requesting the MAPC must include the Co-SR profile in the MAPC element contained in the MAPC Negotiation Request frame that initiates MAPC Agreement negotiations for the Co-SR Agreement.

[0230] The Co-SR profile must include one MAPC Scheme Request field.

[0231] When the MAPC Response AP responds to the MAPC Request AP during MAPC Agreement negotiation for a Co-SR Agreement, it must include the Co-SR profile in the MAPC element contained in the MAPC Negotiation Response frame. The Co-SR profile must include one MAPC Scheme Request field.

[0232] The MAPC requesting AP must not set the MAPC Operation Type field to 1 or 2 if a Co-SR Agreement has not been established between the MAPC requesting AP and the MAPC responding AP. If a Co-SR Agreement has already been established between the MAPC requesting AP and the MAPC responding AP, the MAPC requesting AP must not set the MAPC Operation Type field to 0.

[0233] The MAPC response AP must not set the MAPC Operation Type field included in the MAPC Scheme Request field of the Co-SR profile included in the MAPC Negotiation Response frame to 5.

[0234] (2) Co-SR invitation stage (i.e., Co-SR multiple AP selection procedure / stage)

[0235] The Co-SR cooperating AP must initiate Co-SR transmission with the Co-SR cooperating AP by sending a Co-SR Invite frame to the Co-SR cooperating AP. The Co-SR Invite frame must be a BSRP NTB trigger frame. The TA field of the Co-SR Invite frame must be set to the MAC address of the Co-SR cooperating AP, and the RA field of the Co-SR Invite frame must be set to the MAC address of the Co-SR cooperating AP. The Co-SR Invite frame requests a Co-SR response frame from the Co-SR cooperating AP specified by the Co-SR Invite frame.

[0236] A Co-SR cooperating AP that receives a Co-SR Invite frame must send a Co-SR acknowledgment frame to the Co-SR cooperating AP after aSIFSTime has elapsed since the PPDU delivering the Co-SR Invite frame was terminated. The Co-SR acknowledgment frame must be a multi-terminal BlockAck frame. The TA field of the Co-SR acknowledgment frame must be set to the MAC address of the Co-SR cooperating AP, and the RA field of the Co-SR acknowledgment frame must be set to the MAC address of the Co-SR cooperating AP.

[0237] (3) Co-SR Triggering Procedure / Steps

[0238] The Co-SR cooperating AP must send a Co-SR trigger frame to the Co-SR cooperating AP, and then the Co-SR cooperating AP and the Co-SR cooperating AP simultaneously send data PPDUs.

[0239] 3. Coordinated time division multiple access (Co-TDMA)

[0240] Coordinated time division multiple access (Co-TDMA) procedures allow an AP with dot11CoTDMAOptionImplemented true to sequentially allocate a portion of the acquired TXOPs to one or more non-collocated APs with dot11CoTDMAOptionImplemented true. As part of the Co-TDMA procedure, an AP that receives a time allocation from another AP exchanges one or more PPDUs during the allocated time.

[0241] If any of the following conditions are met, the AP does not initiate the Co-TDMA procedure with another AP.

[0242] ― Cases where there is no MAPC Agreement for Co-TDMA between APs.

[0243] ― When the basic 20MHz channels of the BSS of the two APs are different.

[0244] ― When two APs belong to the same collocated AP set.

[0245] Co-TDMA negotiations for establishing, updating, and releasing the Co-TDMA Agreement must be carried out through MAPC Agreement negotiations / Co-TDMA negotiations or other means.

[0246] Figure 13 shows an example of a Co-TDMA procedure.

[0247] Referring to FIG. 13, the Co-TDMA procedure may include a polling step (i.e., a multiple AP selection procedure / step for Co-TDMA), a TXOP allocation step (i.e., a cooperative trigger procedure / step for Co-TDMA), and / or a TXOP return step. Prior to the Co-TDMA procedure, a MAPC discovery procedure / step and / or Co-TDMA negotiation (i.e., a MAPC Agreement negotiation procedure / step for Co-TDMA) may be performed.

[0248] (1) Co-TDMA negotiation (i.e., MAPC Agreement negotiation procedure / step in the case of Co-TDMA)

[0249] The AP requesting Co-TDMA must include the Co-TDMA profile in the MAPC element contained in the MAPC Negotiation Request frame. The Co-TDMA profile must include one MAPC Scheme Request field.

[0250] The Co-TDMA requesting AP must not set the MAPC Operation Type field to 0 if a Co-TDMA Agreement has already been established between the Co-TDMA requesting AP and the Co-TDMA responding AP.

[0251] If a Co-TDMA Agreement is not established between the Co-TDMA requesting AP and the Co-TDMA responding AP, the Co-TDMA requesting AP must not set the MAPC Operation Type field to 1 or 2.

[0252] An AP that responds to a Co-TDMA requesting AP during MAPC Agreement negotiation for a Co-TDMA Agreement is called a Co-TDMA responding AP. This is a MAPC responding AP and must respond to the Co-TDMA requesting AP according to the rules defined in the MAPC Agreement negotiation. The Co-TDMA responding AP must not set the MAPC Operation Type field included in the MAPC Scheme Request field of the Co-TDMA profile included in the MAPC Negotiation Response frame to 5.

[0253] An AP that has established a Co-TDMA Agreement with a peer AP can operate as both a Co-TDMA cooperative AP and a Co-TDMA cooperative AP.

[0254] (2) Polling step (i.e., multiple AP selection procedure / step for Co-TDMA)

[0255] The Co-TDMA cooperative AP must indicate its intention to allocate a portion of the acquired TXOP to another AP in the ICF transmitted at the start of the TXOP. The ICF polls one or more APs that have established a MAPC Agreement for Co-TDMA with the Co-TDMA cooperative AP, requests a response from the polled APs, and confirms the intention to receive a time allocation from the Co-TDMA cooperative AP within the TXOP.

[0256] A Co-TDMA cooperative AP may request a Co-TDMA ICR in a TB PPDU from another AP that has entered into a MAPC Agreement for Co-TDMA. However, this is only possible if the AP to be polled indicates that it supports the transmission of a Co-TDMA ICR in a TB PPDU by setting the AP TB PPDU Response Support field of the MAPC element to 1.

[0257] An ICF that polls an AP as part of the Co-TDMA process and requests a Co-TDMA ICR from the polled AP in the TB PPDU is called a Co-TDMA TB ICF.

[0258] The Co-TDMA TB ICF must be a BSRP trigger frame.

[0259] An ICF that requests a Co-TDMA ICR for a non-HT PPDU or a non-HT redundant PPDU from a polled AP as part of the Co-TDMA procedure is called a Co-TDMA NTB ICF.

[0260] The Co-TDMA NTB ICF is a BSRP NTB trigger frame, and the GI and HE / UHR-LTF type fields are set to 3.

[0261] To identify the polled AP in the Co-TDMA TB ICF or Co-TDMA NTB ICF, the Co-TDMA cooperative AP sets the AID12 field of the user information field to the AP ID of the polled AP assigned by the Co-TDMA cooperative AP.

[0262] The Duration field of the Co-TDMA TB ICF and Co-TDMA NTB ICF is set to the sum of the time required to transmit the requested Co-TDMA ICR from the AP polled in 1 SIFS.

[0263] When a Co-TDMA cooperative AP transmits a Co-TDMA TB ICF, the AP must set the Feedback Type field of the Feedback User Info field of the Co-TDMA TB ICF to 3.

[0264] When a Co-TDMA cooperative AP transmits a Co-TDMA NTB ICF, the AP must set the Feedback Type field of the User Info field directed to the polled AP to 3.

[0265] The polled AP must transmit a Co-TDMA ICR in response to a received Co-TDMA TB ICF or Co-TDMA NTB ICF containing a User Info field with an AID12 field set to the AP ID of the polled AP assigned by the Co-TDMA cooperative AP.

[0266] The Co-TDMA ICR must be a Multi-STA BlockAck frame containing the following fields in the Per AID TID Info field.

[0267] ― The Feedback Type field must be set to 3.

[0268] ― The AID11 field must be set to 0.

[0269] ― The Ack Type field and TID field must be set to 0 and 13, respectively.

[0270] ― The TXOP Sharing Solicited field of the Feedback field should be set to 1 if the polled AP intends to receive a time allocation from the Co-TDMA cooperating AP during the current TXOP. Otherwise, it should be set to 0.

[0271] If a Co-TDMA cooperative AP does not receive a Co-TDMA ICR from a polled AP, the Co-TDMA cooperative AP should assume that the polled AP does not want to receive a time allocation from the Co-TDMA cooperative AP during the current TXOP.

[0272] The polled AP can determine the value to be set in the "TXOP Sharing Solicited" field of the multi-terminal BlockAck frame using the duration specified in the "Max TXOP Allocation Under Consideration" field of the Co-TDMA ICF.

[0273] When performing Co-TDMA Agreement according to the rules defined in MAPC negotiation and Co-TDMA negotiation, the AP that receives the MAPC Negotiation Request frame can determine the overlapping BSS bandwidth based on the bandwidth setting information included in the bandwidth control field.

[0274] (3) TXOP allocation step (i.e., Co-TDMA cooperative triggering procedure / step)

[0275] To allocate a portion of the acquired TXOPs, the Co-TDMA cooperative AP must send a MU-RTS TXS trigger frame with a TXS mode field of 2 only to the polled AP that is not collocated with the Co-TDMA cooperative AP and has received a Co-TDMA ICR with a TXOP sharing request field of 1.

[0276] Time allocation for the Co-TDMA cooperative AP must begin at the end of the PPDU containing the MU-RTS TXS trigger frame.

[0277] The duration field of the MU-RTS TXS trigger frame must be set to the value of the time required to send the requested CTS response frame in 1 SIFS plus the time required to send the CTS response frame.

[0278] To identify the Co-TDMA cooperative AP to which a portion of the acquired TXOP will be allocated, the Co-TDMA cooperative AP sets the AID12 field of the user information field of the MU-RTS TXS trigger frame to the AP ID of the Co-TDMA cooperative AP allocated by the Co-TDMA cooperative AP.

[0279] When a Co-TDMA cooperative AP receives a MU-RTS TXS trigger frame containing a user information field from a Co-TDMA cooperative AP, and the AP ID of the Co-TDMA cooperative AP is included in the AID12 field of the user information field, the Co-TDMA cooperative AP may exchange one or more PPDUs within the time allocation specified in the MU-RTS TXS trigger frame. The first PPDU of this exchange must transmit a CTS frame.

[0280] The time allocated to the Co-TDMA cooperative AP identified in the MU-RTS TXS trigger frame is specified in the allocation period field of the MU-RTS TXS trigger frame.

[0281] The Co-TDMA cooperative AP can determine the time allocated to the Co-TDMA cooperative AP within the acquired TXOP.

[0282] All frame exchanges between the Co-TDMA cooperative AP and the non-AP connected during the allocated time must be performed in an AC of the same or higher priority as the Primary AC field of the Co-TDMA TB ICF or the Primary AC of the acquired TXOP indicated in the Co-TDMA NTB ICF transmitted by the Co-TDMA cooperative AP during the polling phase of Co-TDMA.

[0283] In a MU-RTS TXS trigger frame that assigns a TXOP to a Co-TDMA cooperative AP, the Co-TDMA cooperative AP must not assign a RU to the Co-TDMA cooperative AP except for the portion where the BSS bandwidth of the Co-TDMA cooperative AP and the PPDU bandwidth transmitting the MU-RTS TXS trigger frame overlap.

[0284] PPDU transmitting a CTS frame transmitted from a Co-TDMA cooperative AP must be transmitted through the 20MHz channel specified in the RU allocation field within the user information field of the MU-RTS TXS trigger frame that allocated time to the Co-TDMA cooperative AP.

[0285] During the time allocated by the Co-TDMA cooperative AP, the Co-TDMA cooperative AP addressed by the MU-RTS TXS trigger frame must not transmit a PPDU using a subchannel other than the subchannel used when transmitting the CTS frame in response to the MU-RTS TXS trigger frame.

[0286] (4) TXOP return step

[0287] If the Co-TDMA cooperative AP indicates TXOP return support by setting the Rx TXOP return support field of the MAPC element to 1, it may return to the Co-TDMA cooperative AP for the remainder of the allocated time (if any). Otherwise, the Co-TDMA cooperative AP does not return the TXOP. If the Co-TDMA cooperative AP is required to return the TXOP to the Co-TDMA cooperative AP, all NAVs set by the Co-TDMA cooperative AP during the allocated time must be terminated before the AP returns the TXOP to the Co-TDMA cooperative AP. Otherwise, all NAVs set by the Co-TDMA cooperative AP during the allocated time are terminated before the allocated period ends.

[0288] If a Co-TDMA cooperative AP needs to return a TXOP, it must not transmit a CF-End frame to cut the TXOP within the allocated time.

[0289] As part of Co-TDMA operation, when a Co-TDMA cooperative AP returns a TXOP to a Co-TDMA cooperative AP, it must direct the TXOP return within the allotted time via a CAS control field where the RDG / More PPDU field is 0. This CAS control field is included in the HE variant HT control field in the MAC header of a MAPC TXOP return frame that contains only the Action field in the frame body.

[0290] When a Co-TDMA cooperative AP receives a TXOP return instruction from a Co-TDMA cooperative AP, it must respond with an Ack frame.

[0291] Other MAPC Public Action frames must not include a CAS control field in the HT control field of the frame MAC header.

[0292] A Co-TDMA cooperative AP that indicates TXOP return support by setting the Rx TXOP return support field in the MAPC element to 1 and requests a TXOP return from the Co-TDMA cooperative AP must set the TXOP return request field of the Co-TDMA TB ICF or Co-TDMA NTB ICF to 1. Otherwise, the Co-TDMA cooperative AP must set the TXOP return request field to 0.

[0293] The Co-TDMA cooperative AP must return a TXOP after receiving a Co-TDMA TB ICF or Co-TDMA NTB ICF with the TXOP return request field set to 1.

[0294] As described above, APs perform a negotiation procedure for the MAPC to establish an agreement for the MAPC, and accordingly, a set of APs with established agreements for the MAPC can be formed (MAPC Agreement Negotiation Procedure / Step). Subsequently, the AP can select an AP from the formed set of APs to perform the MAPC (Multiple AP Selection Procedure / Step). In the Multiple AP Selection Procedure / Step, the AP needs to indicate / report whether or not to participate in the MAPC operation.

[0295] Accordingly, the present disclosure proposes a method for one or more APs to report whether they are participating in a MAPC operation upon receiving a trigger frame (i.e., ICF) transmitted from a Coordinating AP in a procedure for determining whether to participate in a MAPC operation (e.g., multiple AP selection / (cooperative) polling / invitation procedure / schedule notification / cooperative notification). Specifically, signaling bit(s) comprising one or more bits may be used to indicate whether to participate in the MAPC operation or not. Additionally, or alternatively, participation in the MAPC operation may be indicated by transmitting a response frame containing solicited information, and / or non-participation in the MAPC operation may be indicated by setting one or more field(s) within the response frame to zero.

[0296] In the present disclosure, the AP initiating the MAPC and / or triggering the MAPC operation may be referred to as the Coordinating AP (or Sharing AP (SAP)), and the AP receiving the TXOP from the Coordinating AP and / or the AP on which the MAPC operation is triggered may be referred to as the Coordinated AP (or Shared AP (DAP) / Triggered AP / Peer AP). Additionally, or alternatively, the AP transmitting the ICF for the MAPC operation may be referred to as the Coordinating AP (or Sharing AP (SAP)), and the AP addressed and / or polled in the said ICF (e.g., the AP selected in a multiple AP selection procedure / step) may be referred to as the Polled AP (PAP). Furthermore, among one or more polled APs, the AP on which the MAPC operation is finally performed may be referred to as the Coordinated AP (CAP).

[0297] In the present disclosure, “field” and “subfield” may be used interchangeably.

[0298] In the present disclosure, setting a specific field to 0 may include setting all bits of a specific field to 0 and / or setting the value of a specific field to 0.

[0299] Specific designations (names) used in this disclosure may be changed and are not limited thereto.

[0300] FIG. 14 shows an example of a method performed by the first AP to indicate whether to participate in MAPC.

[0301] Referring to FIG. 14, in step S1401, the first AP can establish an agreement for multi-AP cooperation with one or more other APs.

[0302] In step S1403, the first AP may receive an ICF from the second AP among one or more other APs to determine whether to participate in the MAPC operation.

[0303] Step S1405 may include the step of the first AP transmitting an ICR for the ICF to the second AP. The Control Information field within the BSR Control field of the ICR may include one or more fields to indicate whether to participate in the MAPC operation.

[0304] According to various embodiments, one or more fields for indicating participation in MAPC operation may include at least one of an access category index (ACI) Bitmap field, a Delta TID (traffic identifier) ​​field, an ACI High field, a Scaling Factor field, a Queue Size High field, or a Queue Size All field.

[0305] According to various embodiments, the ACI Bitmap field may include a value associated with the access category (AC) for which the buffer status is reported, indicating participation in the MAPC operation. The ACI Bitmap field may be set to 0 to indicate not participating in the MAPC operation.

[0306] According to various embodiments, the ACI Bitmap field may include a value associated with the access category (AC) preferred by the first AP to indicate participation in the MAPC operation. The ACI Bitmap field may be set to 0 to indicate not participating in the MAPC operation.

[0307] According to various embodiments, the Delta TID field may include a value related to the number of TIDs for which the buffer status is reported to indicate participation in the MAPC operation. The ACI Bitmap field and the Delta TID field may be set to 0 to indicate not participating in the MAPC operation.

[0308] According to various embodiments, the ACI High field may indicate participation in the MAPC operation by including a value related to the ACI of the AC where the BSR is indicated in the Queue Size High field. One or more other fields within the ACI High field and the control information field may be set to 0 to indicate that participation in the MAPC operation is not indicated.

[0309] According to various embodiments, the Scaling Factor field may indicate participation in MAPC operation by including values ​​related to the scaling factor (SF) of the Queue Size High field and the Queue Size All field. One or more other fields within the Scaling Factor field and the control information field may be set to 0 to indicate non-participation in MAPC operation. SF may be expressed in octets.

[0310] According to various embodiments, the Queue Size High field may indicate participation in MAPC operation by including a value related to the amount of buffered traffic for the AC identified in the ACI High field. The Queue Size High field may be set to 0 to indicate non-participation in MAPC operation. The amount of buffered traffic may be expressed in SF units.

[0311] According to various embodiments, the Queue Size All field may indicate participation in MAPC operations by including a value related to the amount of buffered traffic for all ACs identified in the ACI Bitmap field. The Queue Size All field may be set to 0 to indicate non-participation in MAPC operations. The amount of buffered traffic may be expressed in SF units.

[0312] According to various embodiments, the reception of the ICF and the transmission of the ICR may be performed in a multiple AP selection procedure for selecting one or more target APs for MAPC operation among one or more other APs.

[0313] According to various embodiments, one or more fields included in the control information field within the BSR control field may indicate participation in the MAPC operation. The first AP may receive a trigger frame from the second AP to trigger the MAPC operation. Based on the reception of the trigger frame, the first AP may perform the MAPC operation with the second AP.

[0314] According to various embodiments, the MAPC operation may be associated with an MAPC method. The MAPC method may include at least one of Co-BF (coordinated beamforming), Co-SR (coordinated spatial reuse), Co-TDMA (coordinated time division multiple access), Co-RTWT (coordinated restricted target wake time), or Co-CR (coordinated channel recommendation).

[0315] According to various embodiments, when the MAPC method is Co-BF or Co-SR, when performing the MAPC operation, while the second AP performs transmission in a time interval to one or more STAs (stations) associated with the second AP, the first AP can perform transmission in a time interval to one or more STAs associated with the first AP.

[0316] According to various embodiments, when the MAPC method is Co-TDMA, frame exchange between the first AP and one or more STAs (stations) associated with the first AP is performed in a first time interval, and frame exchange between the second AP and one or more STAs associated with the second AP can be performed in a second time interval different from the first time interval.

[0317] According to various embodiments, the ICF may be a Co-BF invite frame, a Co-SR invite frame, or a BSRP (buffer status report poll) trigger frame for Co-TDMA. The ICR may be a Co-BF acknowledgment frame, a Co-SR acknowledgment frame, or a Multi-STA (station) BlockAck (block acknowledgement) frame for Co-TDMA.

[0318] Figure 15 shows an example of a method performed by the second AP to verify participation in MAPC.

[0319] Referring to FIG. 15, in step S1501, the second AP can establish an agreement for multi-AP cooperation with one or more other APs.

[0320] In step S1503, the second AP may transmit an ICF to the first AP among one or more other APs to check whether it participates in the MAPC operation.

[0321] In step S1505, the second AP may receive an ICR for the ICF from the first AP. The Control Information field within the BSR Control field of the ICR may include one or more fields to indicate whether to participate in the MAPC operation.

[0322] Below, a detailed explanation regarding instructions on whether to participate in MAPC is provided.

[0323] The present disclosure describes a method in which one or more Coordinated APs, upon receiving an ICF from a Coordinating AP in a procedure for determining participation in a MAPC operation (e.g., multiple AP selection / (cooperative) polling / invitation procedure / schedule announcement / cooperative announcement), report whether they are participating in the MAPC operation through a response frame to the ICF. For example, bit(s) / fields indicating participation in the MAPC operation may be used to indicate participation in the MAPC operation. Additionally or alternatively, if participation in the MAPC operation is indicated, a response frame containing information requested / solicited by the ICF may be transmitted, and if not participation in the MAPC operation is indicated, one or more field(s) within the response frame may all be set to 0.

[0324] A detailed description of how to report participation in MAPC operations is provided below.

[0325] I. Definition of New Signaling Fields

[0326] In some implementations, Coordinated AP(s) that receive the ICF may report whether they are participating in the MAPC operation by responding with a specific value in a newly defined signaling field to indicate whether they are participating in the MAPC operation.

[0327] 1-bit utilization

[0328] In some implementations, a 1-bit signaling bit may be defined to report whether to participate in a solicited MAPC operation from the ICF.

[0329] Participation Indication (1 bit): Indicates whether to participate in the MAPC operation solicited from the ICF.

[0330] That is, the Coordinated AP(s) that have been requested for a response from the Coordinating AP can indicate whether or not to participate in one MAPC operation directed by the current Coordinating AP through a 1-bit participation instruction.

[0331] For example, the reporting of participation in a 1-bit MAPC operation may be as follows:

[0332] - Bit value 0 in the participation indication field: Indicates not to participate in the Solicited MAPC operation.

[0333] - Bit value 1 in the participation instruction field: Indicates participation in the Solicited MAPC operation.

[0334] n-bit utilization

[0335] In some implementations, n bits may be utilized to report whether to participate in the MAPC operation solicited from the ICF and / or the recommendation, reason, etc.

[0336] Participation Indicator (n bits): Indicates whether to participate in the MAPC operation solicited from the ICF.

[0337] That is, the Coordinated AP(s) that have been requested for a response from the Coordinating AP can indicate whether or not to participate in a single MAPC action directed by the current Coordinating AP.

[0338] For example, the report on participation in MAPC operations using n bits can be as follows:

[0339] - Bit value 0 in the participation indication field: Indicates not to participate in the Solicited MAPC operation.

[0340] - Bit value 1 in the participation instruction field: Indicates participation in the Solicited MAPC operation.

[0341] - Bit value 2 of the participation instruction field: Indicates that it includes a proposal to participate in a solicited MAPC operation.

[0342] - Bit value 3 of the participation instruction field: Indicates that it includes a cause for not being able to participate in a solicited MAPC operation.

[0343] Additionally or alternatively, a participation indication field of the same format as the Multi-AP Coordination Type field that may be included in the ICF transmitted by the Coordinating AP may indicate whether to participate in the MAPC operation for a specific MAPC method.

[0344] For example, if the Multi-AP Coordination Type field is defined as 3 bits and the Co-TDMA method is indicated by the Multi-AP Coordination Type field from the Coordinating AP, the Coordinated AP may respond by setting the Multi-AP Coordination Type field to the same bits if it wishes to participate in Co-TDMA, and may respond by setting all values ​​of the Multi-AP Coordination Type field to 0 if it does not wish to participate in the MAPC operation of Co-TDMA.

[0345] For example, if the Multi-AP Coordination Type field is defined with n bits and indicates a specific MAPC method in a bitmap manner, the Coordinated AP may respond by setting the bit corresponding to the MAPC method in the Multi-AP Coordination Type field to 1 if it wishes to participate in the MAPC method, and may respond by setting all values ​​in the Multi-AP Coordination Type field to 0 if it does not wish to participate in the MAPC operation of the MAPC method.

[0346] Example of behavior when defining a new signaling field

[0347] An example of a procedure for reporting participation in MAPC based on the new signaling field described above may be as shown in Fig. 16.

[0348] Figure 16 shows an example of a procedure for reporting participation in MAPC based on a new signaling field.

[0349] Referring to FIG. 16, AP 1 can transmit an ICF (e.g., BSRP TF). AP 4 cannot transmit a response frame to the ICF due to the basic NAV, and AP 2 can indicate via a response frame to the ICF that it will not participate in the MAPC operation directed by the ICF. AP 3 can indicate participation in the MAPC using new signaling field / bit(s) defined in the response frame to the ICF. Based on these response frames, AP 1 transmits a cooperative trigger frame to AP 3, which indicated participation in the MAPC operation, and can perform an MAPC operation (e.g., Co-TDMA / Co-SR / Co-BF) with AP 3.

[0350] II. Set existing field(s) to specific values

[0351] In some implementations, Coordinated AP(s) that receive the ICF may report whether they are participating in the MAPC operation by responding with one or more existing field(s) set to specific values ​​to indicate whether they are participating in the MAPC operation.

[0352] Utilization of the Control Information field within the BSR Control field

[0353] In some implementations, to report participation in a solicited MAPC action from the ICF, one or more field(s) in the Control Information field of the BSR Control field may be set to specific values ​​in response.

[0354] For example, an AP that wishes to participate in the MAPC operation may set the ACI Bitmap field to indicate the access category (AC) to which the buffer status is reported. Alternatively, an AP that wishes to participate in the MAPC operation may set the ACI Bitmap field to indicate the AC value preferred by that AP. On the other hand, an AP that does not wish to participate in the MAPC operation may set the ACI Bitmap field to all zeros.

[0355] Additionally or alternatively, an AP wishing to participate in the MAPC operation may set the Delta TID field to indicate the number of TIDs for which the buffer status is reported. Conversely, an AP wishing not to participate in the MAPC operation may set the Delta TID field to 0. If both the ACI Bitmap field and / or the Delta TID field have a value of 0, the target AP that sent the response frame containing these ACI Bitmap field and / or Delta TID field may be considered not to participate in the MAPC operation.

[0356] Additionally or alternatively, an AP that wishes to participate in the MAPC operation may set the ACI High field to indicate the ACI of the AC where the BSR is indicated in the Queue Size High field. On the other hand, an AP that wishes not to participate in the MAPC operation may set the ACI High field to 0. To indicate that it does not participate in the MAPC operation, in addition to setting the ACI High field to 0, the AP may set one or more other fields (e.g., ACI Bitmap field, Delta TID field) included in the BSR Control field (control information field) to 0.

[0357] Additionally or alternatively, an AP that wishes to participate in the MAPC operation may set the Scaling Factor field to indicate the scaling factor (SF) unit of the Queue Size High and Queue Size All fields in octets. On the other hand, an AP that wishes not to participate in the MAPC operation may set the Scaling Factor field to 0. To indicate that it does not participate in the MAPC operation, in addition to setting the Scaling Factor field to 0, the AP may set one or more other fields included in the BSR Control field (control information field) (e.g., ACI Bitmap field, Delta TID field, ACI High field) to 0.

[0358] Additionally or alternatively, an AP wishing to participate in the MAPC operation can configure the Queue Size High field to indicate the amount of buffered traffic for the AC identified in the ACI High field in units of SF octets. Conversely, an AP wishing not to participate in the MAPC operation can set the Queue Size High field to 0.

[0359] Additionally or alternatively, an AP wishing to participate in the MAPC operation may configure the Queue Size All field to indicate the amount of buffered traffic for all ACs identified in the ACI Bitmap field in units of SF octets. Conversely, an AP wishing not to participate in the MAPC operation may set the Queue Size All field to 0.

[0360] Example of behavior when setting existing field(s) to a specific value

[0361] An example of a procedure for reporting participation in MAPC operations by setting existing field(s) to specific values ​​may be as shown in FIG. 17.

[0362] Figure 17 shows an example of a procedure for reporting participation in MAPC operations by setting existing field(s) to specific values.

[0363] Referring to FIG. 17, AP 1 can transmit an ICF (e.g., BSRP TF). AP 4 cannot transmit a response frame to the ICF due to the basic NAV, and AP 2 can indicate through a response frame to the ICF that it will not participate in the MAPC operation directed by the ICF. AP 3 can indicate participation in the MAPC operation by setting one or more fields included in the BSR Control field of the response frame to the ICF to specific values, or indicate non-participation in the MAPC operation by setting one or more fields included in the BSR Control field to 0. Based on these response frames, AP 1 transmits a cooperative trigger frame to AP 3, which indicated participation in the MAPC operation, and can perform an MAPC operation (e.g., Co-TDMA / Co-SR / Co-BF) with AP 3.

[0364] The present disclosure proposes a method for one or more APs to report whether they are participating in a MAPC operation upon receiving a trigger frame (i.e., ICF) transmitted from a Coordinating AP in a procedure for determining whether to participate in a MAPC operation (e.g., multiple AP selection / (cooperative) polling / invitation procedure / schedule notification / cooperative notification). Specifically, signaling bit(s) comprising one or more bits may be used to indicate whether to participate in the MAPC operation or not. Additionally, or alternatively, participation in the MAPC operation may be indicated by transmitting a response frame containing solicited information, and / or participation in the MAPC operation may be indicated by setting one or more field(s) within the response frame to zero.

[0365] The technical features of the present disclosure described above may be applied to various devices and methods. For example, the technical features of the present disclosure described above may be performed or supported through the device of FIG. 1 and / or FIG. 5. For example, the technical features of the present disclosure described above may be applied only to parts of FIG. 1 and / or FIG. 5. For example, the technical features of the present disclosure 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 (510) and memory (520) of FIG. 5.

[0366] For example, the processor (121) and / or processing chip (124) of FIG. 1 may be configured to perform operations performed by the first AP in the present disclosure by executing instructions stored in memory (122). The operations include: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; receiving an initial control frame (ICF) from a second AP among the one or more other APs to determine whether to participate in the MAPC operation; and transmitting an initial control response frame (ICR) for the ICF to the second AP, wherein the control information field within the buffer status report (BSR) control field of the ICR includes one or more fields to indicate whether to participate in the MAPC operation.

[0367] For example, the processor (111), processing chip (114) of FIG. 1 and / or the processor (510) of FIG. 5 may be configured to execute instructions stored in memory (112, 520) to perform operations performed by the second AP in the present disclosure. The operations include: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; transmitting an initial control frame (ICF) to the first AP among the one or more other APs to check whether to participate in the MAPC operation; and receiving an initial control response frame (ICR) for the ICF from the first AP, wherein the control information field within the buffer status report (BSR) control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

[0368] The technical features of the present disclosure may be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by the present disclosure is at least one computer-readable medium comprising instructions based on execution by at least one processor.

[0369] For example, the CRM may be the memory (122) of FIG. 1 and / or a separate external memory / storage medium / disk. The CRM may store instructions for performing operations performed by the first AP in the present disclosure based on execution by a processor (e.g., the processor (121) and / or processing chip (124) of FIG. 1). The operations include: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; receiving an initial control frame (ICF) from a second AP among the one or more other APs to determine whether to participate in the MAPC operation; and transmitting an initial control response frame (ICR) for the ICF to the second AP, wherein the control information field within the buffer status report (BSR) control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

[0370] For example, the CRM may be the memory (112) of FIG. 1, the memory (520) of FIG. 5, and / or a separate external memory / storage medium / disk. The CRM may store instructions for performing operations performed by the second AP in the present disclosure based on execution by a processor (e.g., the processor (111) of FIG. 1, the processing chip (114), and / or the processor (510) of FIG. 5). The operations include: establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; and transmitting an initial control frame (ICF) to the first AP among the one or more other APs to confirm participation in the MAPC operation. and includes the operation of receiving an ICR (initial control response frame) for the ICF from the first AP, wherein the Control Information field within the BSR (buffer status report) Control field of the ICR includes one or more fields for indicating whether to participate in the MAPC operation.

[0371] The technical features of the present disclosure 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).

[0372] 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.

[0373] 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.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0378] 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.

[0379] 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.

[0380] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0381] 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.

[0382] 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.

[0383] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] The present disclosure may have various advantageous effects.

[0388] For example, by having the first AP report its participation in the MAPC to the second AP, the second AP can quickly identify the set of APs for the cooperation trigger, thereby minimizing the cooperation trigger delay. Additionally, since cooperative operations such as scheduling, beamforming, and interference management are performed based on the APs that have indicated their participation in the MAPC, unnecessary control signal exchanges can be reduced, and cooperation efficiency can be improved.

[0389] Furthermore, by clearly identifying participation in MAPC, role sharing and resource allocation among APs can be performed more accurately, resulting in improved network throughput, reduced latency, and the stable securing of multi-AP-based transmission performance.

[0390] The advantageous effects obtainable through specific embodiments of the present disclosure are not limited to those listed above. For example, there may be various technical effects that a person skilled in the art can understand and / or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein and may include various effects that can be understood or derived from the technical features of the present disclosure.

[0391] The claims described in this disclosure may be combined in various ways. For example, the technical features of the method claims of this disclosure may be combined to be implemented as a device, and the technical features of the device claims of this disclosure may be combined to be implemented as a method. Additionally, the technical features of the method claims of this disclosure and the technical features of the device claims of this disclosure may be combined to be implemented as a device, and the technical features of the method claims of this disclosure and the technical features of the device claims of this disclosure may be combined to be implemented as a method.

Claims

1. A step in which the first AP (access point) establishes an agreement with one or more other APs for multi-AP coordination (MAPC); The first AP receives an initial control frame (ICF) from the second AP among the one or more other APs to determine whether to participate in the MAPC operation; and The above first AP includes the step of transmitting an ICR (initial control response frame) for the ICF to the above second AP, and A method in which the Control Information field within the BSR (buffer status report) Control field of the above ICR includes one or more fields for indicating whether to participate in the MAPC operation.

2. A method according to claim 1, wherein one or more fields for indicating participation in the MAPC operation include at least one of an ACI (access category index) Bitmap field, a Delta TID (traffic identifier) ​​field, an ACI High field, a Scaling Factor field, a Queue Size High field, or a Queue Size All field.

3. In claim 2, the ACI Bitmap field indicates participation in the MAPC operation by including a value associated with the access category (AC) where the buffer status is reported, and A method in which the above ACI Bitmap field is set to 0 to indicate that it does not participate in the above MAPC operation.

4. In claim 2, the ACI Bitmap field indicates participation in the MAPC operation by including a value associated with an AC (access category) preferred by the first AP, and A method in which the above ACI Bitmap field is set to 0 to indicate that it does not participate in the above MAPC operation.

5. In claim 2, the Delta TID field indicates that it participates in the MAPC operation by including a value related to the number of TIDs for which the buffer state is reported, and A method in which the above ACI Bitmap field and the above Delta TID field are set to 0 to indicate that they do not participate in the above MAPC operation.

6. In claim 2, the ACI High field indicates participation in the MAPC operation by including a value related to the ACI of the AC where the BSR is indicated in the Queue Size High field, and A method of indicating that one or more other fields within the above ACI High field and the above control information field are set to 0 to indicate that they do not participate in the above MAPC operation.

7. In claim 2, the Scaling Factor field indicates participation in the MAPC operation by including a value related to the scaling factor (SF) of the Queue Size High field and the Queue Size All field, and One or more other fields within the Scaling Factor field and the control information field are set to 0 to indicate that they do not participate in the MAPC operation, and The above SF is a method of expressing in octets.

8. In claim 2, the Queue Size High field indicates participation in the MAPC operation by including a value related to the amount of buffered traffic for the AC identified in the ACI High field, and The above Queue Size High field is set to 0 to indicate that it does not participate in the above MAPC operation, and A method in which the amount of buffered traffic is expressed in SF units.

9. In claim 2, the Queue Size All field indicates participation in the MAPC operation by including a value related to the amount of buffered traffic for all ACs identified in the ACI Bitmap field, and The above Queue Size All field is set to 0 to indicate that it does not participate in the above MAPC operation, and A method in which the amount of buffered traffic is expressed in SF units.

10. The method of claim 1, wherein the reception of the ICF and the transmission of the ICR are performed in a multiple AP selection procedure for selecting one or more target APs for the MAPC operation among one or more other APs.

11. In claim 1, the one or more fields included in the control information field within the BSR control field indicate that they participate in the MAPC operation, and The first AP receives a trigger frame from the second AP to trigger the MAPC operation; and A method further comprising the step of the first AP performing the MAPC operation with the second AP based on the reception of the trigger frame.

12. In claim 11, the MAPC operation is related to the MAPC method, and The above MAPC method is a method comprising at least one of Co-BF (coordinated beamforming), Co-SR (coordinated spatial reuse), Co-TDMA (coordinated time division multiple access), Co-RTWT (coordinated restricted target wake time), or Co-CR (coordinated channel recommendation).

13. A method according to claim 12, wherein the MAPC method is the Co-BF or the Co-SR, wherein the step of performing the MAPC operation includes the step of the first AP performing transmission in the time interval to one or more STAs (stations) associated with the second AP while the second AP performs transmission in the time interval.

14. In claim 12, based on the fact that the MAPC method is Co-TDMA: Frame exchange between the first AP and one or more STAs (stations) associated with the first AP is performed in a first time interval, and A method in which frame exchange between the second AP and one or more STAs connected to the second AP is performed in a second time interval different from the first time interval.

15. In claim 1, the ICF is a Co-BF invite frame, a Co-SR invite frame, or a BSRP (buffer status report poll) trigger frame for Co-TDMA, and The above ICR is a method in which the ICR is a Co-BF response frame, a Co-SR response frame, or a Multi-STA (station) BlockAck (block acknowledgement) frame for Co-TDMA.

16. At the first AP (access point), Transmitter / Receiver; Memory; and It includes at least one processor functionally coupled with the above-mentioned transceiver and the above-mentioned memory, and The above memory stores instructions for performing operations based on execution by the at least one processor, and the operations are: The action of establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; The operation of receiving an ICF (initial control frame) from a second AP among the one or more other APs above to determine whether to participate in the MAPC operation; and The operation includes transmitting an ICR (initial control response frame) for the ICF to the second AP, and The Control Information field within the BSR (buffer status report) Control field of the above ICR is a first AP comprising one or more fields for indicating whether to participate in the MAPC operation.

17. In the device, At least one processor; and It includes at least one memory functionally coupled with the above-mentioned at least one processor, and The above at least one memory stores instructions for performing operations based on execution by the above at least one processor, and the operations are: The operation of the first AP (access point) establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; The operation of the first AP receiving an initial control frame (ICF) from the second AP among the one or more other APs to determine whether to participate in the MAPC operation; and The above first AP includes the operation of transmitting an ICR (initial control response frame) for the above ICF to the above second AP, and A device in which the Control Information field within the BSR (buffer status report) Control field of the above ICR includes one or more fields for indicating whether to participate in the above MAPC operation.

18. In a non-transitory computer-readable medium (CRM) storing program code that implements instructions for performing operations based on execution by at least one processor, said operations are: The operation of the first AP (access point) establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; The operation of the first AP receiving an initial control frame (ICF) from the second AP among the one or more other APs to determine whether to participate in the MAPC operation; and The above first AP includes the operation of transmitting an ICR (initial control response frame) for the above ICF to the above second AP, and The Control Information field within the BSR (buffer status report) Control field of the above ICR is a CRM that includes one or more fields for indicating whether to participate in the above MAPC operation.

19. A step in which the second AP (access point) establishes an agreement with one or more other APs for multi-AP coordination (MAPC); The step of the second AP transmitting an initial control frame (ICF) to the first AP among the one or more other APs to determine whether it participates in the MAPC operation; and The above-mentioned second AP includes the step of receiving an ICR (initial control response frame) for the ICF from the above-mentioned first AP, and A method in which the Control Information field within the BSR (buffer status report) Control field of the above ICR includes one or more fields for indicating whether to participate in the MAPC operation.

20. In the second AP (access point), Transmitter / Receiver; Memory; and It includes at least one processor functionally coupled with the above-mentioned transceiver and the above-mentioned memory, and The above memory stores instructions for performing operations based on execution by the at least one processor, and the operations are: The action of establishing an agreement for multi-AP coordination (MAPC) with one or more other APs; The operation of transmitting an ICF (initial control frame) to the first AP among the above one or more other APs to check whether it participates in the MAPC operation; and The operation includes receiving an ICR (initial control response frame) for the ICF from the first AP, and The Control Information field within the BSR (buffer status report) Control field of the above ICR is a second AP comprising one or more fields for indicating whether to participate in the above MAPC operation.

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