Critical update related to non-primary channel access in wireless LAN system

Abstract

The present disclosure relates to a critical update related to non-primary channel access (NPCA) in a wireless LAN system. According to an embodiment of the present disclosure, a method performed by an access point (AP) in a wireless LAN system comprises the steps of: on the basis that updates on one or more parameters for non-primary channel access (NPCA) are present, setting at least one of a critical update flag and a BSS parameter change count field to a corresponding value; and transmitting a frame comprising at least one of the critical update flag and the BSS parameter change count field, wherein the frame comprises a parameters update element, and the parameters update element comprises one or more parameters for the NPCA.

Description

Important updates related to non-primary channel access in wireless LAN systems

[0001] This disclosure relates to a critical update related to non-primary channel access (NPCA) in a wireless LAN system.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability when transmitting signals to STAs, and to this end, various technologies are being considered to support high throughput, low latency, and extended range.

[0003] In a wireless LAN system, the AP transmits various parameter information necessary for BSS operation to the terminal via non-frames or probe response frames. Based on this parameter information, the terminal establishes a connection with the AP and transmits and receives data.

[0004] AP BSS parameters may be updated due to changes in the wireless environment or network settings, and a Critical Update mechanism is defined to efficiently manage these changes. Updates to specific parameters (e.g., addition, deletion, or modification) may be classified as critical updates. For example, updates to parameters related to NPCA may be classified as critical updates.

[0005] The present disclosure provides a method and apparatus for important updates related to NPCA in a wireless LAN system.

[0006] According to an embodiment of the present disclosure, a method performed by an access point (AP) in a wireless LAN system comprises: setting at least one of a critical update flag or a BSS parameter change count field to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA); and transmitting a frame including at least one of the critical update flag or the BSS parameter change count field, wherein the frame includes a parameter update element, and the parameter update element includes one or more parameters for the NPCA.

[0007] According to an embodiment of the present disclosure, a method performed by a STA (station) in a wireless LAN system comprises: receiving a frame including at least one of a critical update flag or a basic service set (BSS) parameter change count field; and obtaining a parameter update element in the frame based on at least one of the critical update flag or the BSS parameter change count field, wherein at least one of the critical update flag or the BSS parameter change count field is set to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA), and the parameter update element includes one or more parameters for the NPCA.

[0008] In various embodiments, devices for implementing the methods described above are provided.

[0009] The present disclosure may have various advantageous effects.

[0010] For example, by transmitting parameters related to NPCA as critical updates only when an update (e.g., addition / modification / change) of the parameter occurs, overhead can be reduced compared to a method in which parameters related to NPCA are transmitted via beacons, probe response frames, etc., every cycle (i.e., different from critical updates).

[0011] 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.

[0012] FIG. 1 shows an example of a transmitting device and / or receiving device of the present disclosure.

[0013] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0014] Figure 3 is a diagram illustrating a general link setup process.

[0015] Figure 4 illustrates an example of multiple links.

[0016] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0017] 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.

[0018] Figure 7 shows the operation according to UL-MU.

[0019] Figure 8 shows an example of a MAC frame header.

[0020] Figure 9 shows an example of a multi-link element format.

[0021] Figure 10 shows an example of the Common Info field format of Basic ML IE.

[0022] Figure 11 shows an example of the Per-STA Profile subelement format of Basic ML IE.

[0023] Figure 12 shows an example of a random backoff procedure.

[0024] Figure 13 shows an example of a critical update procedure in a multi-link environment.

[0025] Figure 14 shows an example of the MLD Parameters subfield format.

[0026] FIG. 15 illustrates an example of a method performed by AP for an important update related to NPCA according to various embodiments of the present disclosure.

[0027] FIG. 16 illustrates an example of signal flow between an AP MLD and a non-AP MLD for important updates related to NPCA according to various embodiments of the present disclosure.

[0028] Figure 17 shows an example where the UHR BPCC corresponding to the Reporting AP is included in the Common Info field of the Basic ML IE.

[0029] Figure 18 shows an example of the Presence Bitmap field format of Basic ML IE including UHR BPCC.

[0030] Figure 19 shows an example where the UHR BPCC corresponding to the Reporting AP is included in the Link Info field of the Basic ML IE.

[0031] Figure 20 shows an example of the STA Control field format of Basic ML IE including UHR BPCC.

[0032] Figure 21 shows an example of a TBTT Information field format including a UHR BPCC corresponding to a Reported AP.

[0033] Figure 22 shows an example of a Basic ML IE format containing a UHR BPCC corresponding to a Reported AP.

[0034] Figure 23 shows an example where UHR BPCC is included in the STA Control field corresponding to the Reported AP.

[0035] Figure 24 shows an example of operation classes for channel numbers.

[0036] Figure 25 shows an example of the Parameters Update field / element format.

[0037] Figure 26 shows examples of UHR Feature / Modes included in the Parameters Update field / element.

[0038] Figure 27 shows an example of a case where the Parameters Update field / element is indicated based on the Parameters Update Present field.

[0039] Figure 28 shows examples of UHR Feature / Modes included in the Parameters Update field / element indicated based on the Parameters Update Present field.

[0040] Figure 29 shows an example where the Parameters Update field / element is included in the Link Info field.

[0041] Figure 30 shows an example where the Parameters Update field / element corresponding to the Reported AP is included in the Link Info field.

[0042] Figure 31 shows an example where each field included in the Updated Parameters for NPCA field is defined at a fixed position.

[0043] Figure 32 shows an example of the Updated Parameters for NPCA field format based on the Type field.

[0044] Figures 33a and 33b show the first example of a UHR critical update.

[0045] Figures 34a and 34b show a second example of a UHR critical update.

[0046] Figure 35 shows an example of a Capability Information field format including an Enhanced Critical Update Flag field.

[0047] Figure 36 shows an example of an Enhanced Critical Updates Information field format including an Enhanced BSS Parameter Change Count field.

[0048] Figure 37 shows an example of a TBTT Information field format including an Enhanced Critical Updates Information field.

[0049] Figure 38 shows an example of the Presence Bitmap subfield format of Basic ML IE.

[0050] Figure 39 shows an example of the STA Control field format of Basic ML IE.

[0051] Figure 40 shows an example of the UHR Parameters Update element format.

[0052] Figure 41 shows an example of a Mode Tuple field format.

[0053] Figure 42 shows an example of the Mode Specific Parameters field format for NPCA.

[0054] 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.”

[0055] 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.”

[0056] 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.”

[0057] 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.”

[0058] 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.”

[0059] 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.”

[0060] Technical features described individually within one drawing in this disclosure may be implemented individually or simultaneously.

[0061] 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.

[0062] To explain the technical features of the present disclosure, the technical features to which the present disclosure can be applied are described below.

[0063] FIG. 1 shows an example of a transmitting device and / or receiving device of the present disclosure.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] Based on side drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0069] 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.

[0070] 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.).

[0071] 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).

[0072] 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.).

[0073] 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).

[0074] For example, the operation of the device designated as AP in the following disclosure 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 designated as AP is controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). Additionally, control information related to the operation of the AP or the transmission / reception signal 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 designated as AP is controlled by the processor (121) of the second STA (120), and a related signal may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or the transmission / reception signals of the AP can be stored in the memory (122) of the second STA (110).

[0075] For example, the operation of a device indicated as non-AP (or User-STA) in the following disclosure 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 a related signal 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 signal of the AP may be stored in the memory (122) of the second STA (120). For example, if the first STA (110) is a non-AP, the operation of 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).

[0076] In the following disclosure, a device referred to as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, a device indicated without specific drawing symbols as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may also refer to the STA (110, 120) of FIG. 1. For example, in the following example, the operation of various STAs transmitting and receiving signals (e.g., PPDU) may be performed by the transceivers (113, 123) of FIG. 1. Additionally, in the following example, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processors (111, 121) of FIG. 1.For example, an example of an operation to generate a transmission / reception signal or to perform data processing or operations in advance for a transmission / reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of sub-fields (SIG, STF, LTF, Data) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 4) a power control operation and / or power saving operation applied to the STA; and 5) an operation related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. In addition, in the following example, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals can be stored in the memory (112, 122) of FIG. 1.

[0077] 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.

[0078] 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.

[0079] 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).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0085] The top of Figure 2 shows the structure of the basic service set (BSS) infrastructure of IEEE (Institute of Electrical and Electronic Engineers) 802.11.

[0086] 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).

[0087] 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.

[0088] 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).

[0089] 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).

[0090] 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).

[0091] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0092] 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.

[0093] Figure 3 is a diagram illustrating a general link setup process.

[0094] 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.

[0095] 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).

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] The following describes multi-link (ML).

[0103] Terms related to multiple links can be defined as follows:

[0104] - An MLD (multi-link device) may refer to a logical entity that can support multiple affiliated STAs, can operate using one or more affiliated STAs, and provides one MAC data service and a single MAC service access point (SAP) to a logical link control (LLC) sublayer;

[0105] - Multi-link operation (MLO) can refer to operations such as discovery, authentication, multi-link establishment, and frame switching between two MLDs;

[0106] - An associated STA is a STA that provides link-specific downstream MAC and PHY services within an MLD, and may be an AP (Access Point) STA or a non-AP (Non-Access Point) STA;

[0107] - An AP MLD is an MLD where each STA associated with it is an AP;

[0108] - A non-AP MLD is an MLD in which each STA associated with it is a non-AP STA;

[0109] - The linked AP is the AP STA linked to the AP MLD;

[0110] - The linked non-AP STA is the non-AP STA linked to the non-AP MLD.

[0111] Figure 4 illustrates an example of multiple links.

[0112] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate through multiple links. 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).

[0113] 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.

[0114] 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.

[0115] In an example of FIG. 4, AP1 may initiate a multilink setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In an example of FIG. 4, non-AP STA1 may transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) shown in FIG. 4 may be identical to 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 identical to the STA shown in FIG. 1 and / or FIG. 2 (i.e., user-STA or non-AP STA). Once the ML setup is complete, an enabled link for ML communication may be determined. The STA may perform frame exchange through at least one of the multiple links determined as the enabled link. For example, the enabled link may be used for at least one of a management frame, a control frame, and a data frame.

[0116] When a single STA supports multiple links, the transmitting and receiving devices supporting each link can operate as a single logical STA. For example, a single STA supporting two links can be represented as a single Multi-Link Device (MLD) comprising a first STA for the first link and a second STA for the second link. For example, a single AP supporting two links can be represented as a single AP MLD comprising a first AP for the first link and a second AP for the second link. Additionally, a single non-AP supporting two links can be represented as a single non-AP MLD comprising a first STA for the first link and a second STA for the second link.

[0117] Below, more specific features regarding the ML setup are explained.

[0118] An MLD (AP MLD and / or non-AP MLD) may transmit information regarding links that the MLD can support through an ML setup. Information regarding links may be configured in various ways. For example, information regarding links may include at least one of: 1) information regarding whether the MLD (or STA) supports simultaneous RX / TX operation; 2) information regarding the number / upper limit of uplink / downlink links supported by the MLD (or STA); 3) information regarding the location / band / resource of uplink / downlink links supported by the MLD (or STA); 4) information regarding the type of frame (management, control, data, etc.) available or preferred on at least one uplink / downlink link; 5) information regarding the ACK policy available or preferred on at least one uplink / downlink link; and 6) information regarding the TID (traffic identifier) ​​available or preferred on at least one uplink / downlink link. TID is related to the priority of traffic data and is expressed as 8 types of values ​​according to conventional wireless LAN standards. That is, 8 TID values ​​can be defined corresponding to the 4 access categories (AC) (AC_BK (background), AC_BE (best effort), AC_VI (video), AC_VO (voice)) according to conventional wireless LAN standards.

[0119] For example, all TIDs can be pre-configured to be mapped to the uplink / downlink Link. Specifically, if no negotiation is made through the ML setup, all TIDs are used for ML communication, and if a mapping between the uplink / downlink Link and the TID is negotiated through additional ML setup, the negotiated TID can be used for ML communication.

[0120] Through ML setup, multiple links that can be used by the transmitting MLD and receiving MLD related to ML communication can be established, and these can be called “enabled links.” “Enabled links” can be referred to by various other expressions. For example, they can be referred to by various expressions such as the first link, the second link, the transmitting link, and the receiving link.

[0121] After the ML setup is completed, the MLD can update the ML setup. For example, if the MLD needs to update information about a link, it can transmit information about a new link. Information about a new link may be transmitted based on at least one of a management frame, a control frame, and a data frame.

[0122] 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.

[0123] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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).

[0133] Each block shown in FIG. 6 can be referred to as a field / subfield / signal, etc. As shown 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.

[0134] 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.

[0135] 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).

[0136] 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.

[0137] 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}.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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".

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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).

[0154] 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).

[0155] 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.

[0156] 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.

[0157] 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).

[0158] 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.

[0159] 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.

[0160] 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).

[0161] 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).

[0162] The structure and types / subtypes of MAC frames are described below.

[0163] FIG. 8 shows an example of a MAC frame header. As illustrated, the MAC frame may include a frame control field / information of 2 octets, a duration field / information of 2 octets, a Receiver Address (RA) field / information of 6 octets, and a Transmitter Address (TA) field / information of 6 octets. As illustrated in FIG. 8, the four fields may be consecutive. 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.

[0164] 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 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 a PPDU (e.g., UHR PPDU).

[0165] 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.

[0166] 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 value of the type field (B3 and B2) of the MAC header is set to 00. Additionally, the value of the subtype field (B7, B6, B5, B4) of the MAC header is 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).

[0167] 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) of the MAC header are set to 01. Also, the values ​​of the subtype fields (B7, B6, B5, B4) of the MAC header are as follows: Trigger(0010), Beamforming Report Poll(0100), NDP Announcement(0101), Control Frame Extension(0110), Control Wrapper(0111), BlockAckReq(1000), BlockAck(1001), PS-Poll(1010), RTS(1011), CTS(1100), Ack(1101), CF-End(1110).

[0168] For example, the data frame includes (QoS) Data, (QoS) Null, etc., defined in conventional WLANs. For the data frame, the value of the type field (B3 and B2) of the MAC header is set to 10.

[0169] The MAC frames / signals used in this disclosure can be identified through the type field / information and subtype field / information described above. The various MAC frames described in this disclosure are inserted / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDUs).

[0170] Figure 9 shows an example of a multi-link element format.

[0171] Referring to FIG. 9, a Multi-link (ML) element (or ML IE) may include a Multi-link Control field, a Common Info field, and a Link Info field. The Multi-link Control field includes a Type subfield, and the Type subfield is used to distinguish variants of the ML IE. For example, if the value of the Type subfield is 0, the variant of the ML IE may be Basic ML IE.

[0172] Figure 10 shows an example of the Common Info field format of Basic ML IE.

[0173] Referring to FIG. 10, the Common Info field of the Basic ML IE may include a BSS Parameters Change Count subfield. The BSS Parameters Change Count subfield carries a non-negative integer initialized to 0. If a significant update occurs to the BSS parameter of an AP associated with an AP MLD included in the Basic ML IE, and the AP satisfies one of the following, the value of the subfield increases by 1 (modulo 256, excluding 255):

[0174] - If it is the AP that transmitted the corresponding Basic ML IE.

[0175] - In the case of an AP corresponding to a Nontransmitted BSSID that is a member of the same Multiple BSSID set as the AP that transmitted a Multiple BSSID element containing a profile for the Nontransmitted BSSID (provided that the profile includes Basic ML IE).

[0176] The BSS Parameters Change Count subfield exists in the Common Info field when the Basic Multi-Link element is carried in a Management frame transmitted by the AP. However, Authentication frames are an exception.

[0177] The Link Info field may include one or more Per-STA Profile subelements.

[0178] Figure 11 shows an example of the Per-STA Profile subelement format of Basic ML IE.

[0179] Referring to Fig. 11, the Per-STA Profile subelement of Basic ML IE may include a Subelement ID subfield, a Length subfield, an STA Control subfield, an STA Info subfield, and / or an STA Profile subfield.

[0180] The following is a description of channel access.

[0181] STAs with data to transmit can perform a Clear Channel Assessment (CCA) to sense the medium for a specific period (e.g., the Distributed Coordination Function (DCF) inter-frame space) before transmitting the data. If the medium is idle, the STA can use that medium to perform transmission. However, if the medium is busy, it can be assumed that multiple STAs are already waiting to use it, and the STA can transmit data after waiting for a random backoff period in addition to the DIFS. In this case, the random backoff period enables collision avoidance because, assuming there are multiple STAs to transmit data, each STA probabilistically takes on a different backoff period value, resulting in different transmission times. Once one STA begins transmission, other STAs are unable to use that medium.

[0182] In the random backoff procedure, when a specific medium transitions from an active state to an idle state, multiple STAs begin preparing to send data. To minimize collisions at this time, STAs intending to transmit data each select a random backoff count and wait for the slot time corresponding to the selected counter. The random backoff count is a pseudo-random integer value, selecting one of the uniformly distributed values ​​within the range [0 CW]. CW stands for contention window. The CW parameter takes the initial value CWmin, but if transmission fails, the value is doubled. For example, if an ACK acknowledgment for a transmitted data frame is not received, it can be considered that a collision has occurred. If the CW value reaches CWmax, it is maintained until data transmission is successful; upon successful transmission, the CW value is reset to CWmin. In this case, CW, CWmin, and CWmax are used for the convenience of implementation and operation. It can be expressed as follows. Meanwhile, when the random backoff procedure starts, the STA selects a random backoff count within the range [0 CW] and continues to monitor the media while the backoff slots are counting down. During this time, if the media becomes in use, the countdown is stopped, and when the media becomes idle again, the countdown for the remaining backoff slots is resumed.

[0183] Figure 12 shows an example of a random backoff procedure.

[0184] Referring to Fig. 12, when multiple STAs have data they wish to send, STA3 can immediately transmit the data frame because the medium is idle for DIFS, while the other STAs wait for the medium to become idle. Since the medium has been idle for a while, multiple STAs will be looking for an opportunity to use it. Therefore, each STA selects a random backoff count, and STA 2, which selects the smallest backoff count, can transmit the data frame. After STA 2 finishes transmitting, the medium becomes idle again, and the STAs resume counting down for the backoff intervals that had been paused. STA 5, which has the next smallest random backoff count value after STA 2 and paused its countdown while the medium was in use, counts down the remaining backoff slots and begins transmitting the data frame, but a collision may occur if it happens to overlap with the random backoff count value of STA 4. At this time, since neither STA receives an ACK response after data transmission, the two STAs double the CW and then select a random backoff count value again.

[0185] The following is an explanation regarding NPCA (non-primary channel access).

[0186] Non-Primary Channel Access (NPCA) is a channel access method that allows terminals belonging to an overlapping Basic Service Set (OBSS) to switch to an alternative channel instead of the primary channel for a certain period of time to communicate when activity of an overlapping BSS is detected in a portion of the frequency band where a Basic Service Set (BSS) is operating in a wireless LAN system. This improves communication continuity and channel utilization efficiency even in environments where OBSS interference occurs.

[0187] Non-AP terminals supporting NPCA operation are defined as NPCA non-AP STAs, and access points supporting NPCA operation are defined as NPCA APs. APs and STAs supporting NPCA functions can mutually recognize whether they support the function through capability information, and a non-AP STA can activate NPCA mode only when associated with an AP that has NPCA functionality enabled. Additionally, upon (re)association, a non-AP STA starts with NPCA mode disabled by default, and negotiation with the AP is required according to the defined operation mode update procedure to activate NPCA mode or update related parameters.

[0188] NPCA is restricted to operating only on BSSs with a bandwidth above a certain level; for example, APs with an operating bandwidth of less than 80 MHz cannot enable NPCA operation. When NPCA is enabled, the AP notifies non-AP STAs of NPCA-related parameters such as the NPCA default channel, minimum operation duration, switching delay, and switch back delay. These parameters are transmitted via beacons, (re)association response frames, and other management frames, and can be consistently configured across the same set of multiple BSSIDs or co-hosted BSSs.

[0189] During NPCA operation, the STA communicates primarily through the NPCA primary channel rather than the BSS primary channel. In this case, the NPCA primary channel is defined to be located within the secondary channel of the BSS operation channel, and a channel within the corresponding secondary channel is selected based on the total bandwidth of the BSS (e.g., 80 MHz, 160 MHz, 320 MHz). Additionally, during NPCA operation, some 20 MHz subchannels may be designated not to be used, and this subchannel disablement information is transmitted via the NPCA Disabled Subchannel Bitmap. This enables flexible bandwidth management in conjunction with preamble puncturing.

[0190] In an environment where NPCA is enabled, PHY parameters related to spatial reuse may also be restricted, and the AP may be configured not to allow spatial reuse before and during NPCA operation. This is a measure to minimize the possibility of inter-channel interference during NPCA operation.

[0191] In summary, NPCA is a mechanism that allows terminals within a BSS to temporarily switch to an alternative communication path using an auxiliary channel in response to partial channel interference in a wireless LAN environment using a wide bandwidth, and aims to mitigate OBSS interference, improve channel utilization efficiency, and maintain communication quality.

[0192] Meanwhile, if an update (e.g., addition and / or modification / change) occurs for at least one specific element (e.g., an element within the element list of Critical Update) in a Beacon and / or Probe Response frame, such update may be considered a critical update. That is, the STA recognizes that a critical update has occurred and can verify the modification / change and / or addition of the IE that occurred in the critical update in the corresponding frame (e.g., Beacon and / or Probe Response frame). For example, in a multi-link environment, instructions and / or information regarding the occurrence of a critical update on another link may be transmitted from one link.

[0193] In the present disclosure, the following events (e.g., events regarding the BSS parameters of an AP) may be classified as important updates:

[0194] a) Inclusion of Channel Switch Announcement element

[0195] b) Inclusion of Extended Channel Switch Announcement element

[0196] c) Modification of EDCA Parameters element

[0197] d) Inclusion of Quiet element

[0198] e) Modification of DSSS Parameter Set

[0199] f) Modification of HT Operation element

[0200] g) Inclusion of Wide Bandwidth Channel Switch element

[0201] h) Inclusion of Channel Switch Wrapper element

[0202] i) Inclusion of Operating Mode Notification element

[0203] j) Inclusion of Quiet Channel element

[0204] k) Modification of VHT Operation element

[0205] l) Modification of HE Operation element

[0206] m) Insertion of Broadcast TWT elements

[0207] m1) Insertion or removal of the Broadcast TWT Parameter Set field within a Broadcast TWT element

[0208] n) Inclusion of BSS Color Change Announcement element

[0209] o) Modification of MU EDCA Parameter Set elements

[0210] p) Modification of Spatial Reuse Parameter Set element

[0211] q) Modification of UORA Parameter Set elements

[0212] r) Insertion of the Index Adjustment Factor field within the Multiple BSSID Configuration element

[0213] r1) Modification of EHT Operation element

[0214] r2) If the AP is an EHT AP, include, modify, or remove the Transmit Power Envelope element

[0215] The list of events mentioned above can be referred to as the event list of important updates (or, the element list of important updates).

[0216] In the present disclosure, important update procedures (e.g., important update procedures for BSS parameters) are as follows.

[0217] AP MLD linked APs (reporting APs) that are not included in the Multiple BSSID set or correspond to Transmitted BSSIDs within the Multiple BSSID set must perform the following:

[0218] - The BSS Parameters Change Count subfield for each AP associated with the same AP MLD as the reporting AP must be included in the Beacon and Probe Response frames transmitted by the user, and the BSS Parameters Change Count subfield for each AP for which (re)establishment was requested in the received (Re)Association Request frame must be included in the (Re)Association Response frame transmitted by the user.

[0219] The BSS Parameters Change Count subfield value for each AP is initialized to 0 and must be increased by 1 when a critical update occurs to the BSS parameter of the corresponding AP (modulo 256 method excluding 255).

[0220] In beacon and probe response frames, the BSS Parameters Change Count subfield for each of the other AP(s) associated with the AP MLD must be transmitted in the MLD Parameters subfield within the TBTT Information field of the Reduced Neighbor Report (RNR) element corresponding to the AP, wherein each of the other AP(s) is identified by the Link ID subfield of the MLD Parameters subfield.

[0221] In the (re)connection response frame, the BSS Parameters Change Count subfield for each of the other AP(s) for which (re)connection was requested in the received (re)connection request frame, which is associated with the AP MLD, must be transmitted in the STA Info subfield within the Per-STA Profile subelement of the Basic Multi-Link element corresponding to the AP, wherein each of the other AP(s) is identified by the Link ID subfield within the STA Control field of the Per-STA Profile subelement.

[0222] The BSS Parameters Change Count subfield for the reporting AP must be transmitted in the Common Info field of the Basic Multi-Link element, and the reporting AP is identified by the Link ID subfield of the Common Info field.

[0223] - If at least one of the following conditions is met, the Critical Update Flag subfield of the Capability Information field in the beacon and probe response frame is set to 1 until the reporting AP includes the next DTIM beacon on the link in operation.

[0224] If there is a change in the BSS Parameters Change Count subfield value of the MLD Parameters field within the Reduced Neighbor Report (RNR) element for any AP linked to the same AP MLD as the reporting AP, or the BSS Parameters Change Count subfield value within the Common Info field of the Basic Multi-Link element.

[0225] When a new linked AP is added to an AP MLD linked to a reported AP.

[0226] When a Reconfiguration Multi-Link element is included or a new Per-STA Profile subelement is added and modified by a Report AP linked to the AP MLD.

[0227] If an AP associated with the same AP MLD as the reporting AP is disabled or enabled via a new advertised TTLM. Otherwise, set the Critical Update Flag subfield of the Capability Information field to 0.

[0228] ― For each reported AP associated with the same AP MLD as the reporting AP, if updated elements corresponding to the latest critical update that caused a change in the BSS Parameters Change Count value of the reported AP are included in the frame carrying the RNR element, the All Updates Included subfield in the MLD Parameters subfield within the TBTT Information field of the RNR element corresponding to the AP is set to 1. This subfield remains at 1 until updated elements are no longer included or the BSS Parameters Change Count subfield is further increased due to another critical update, otherwise it is set to 0.

[0229] If the AP associated with the AP MLD is a Nontransmitted BSSID within a Multiple BSSID set, the AP corresponding to the Transmitted BSSID within the same Multiple BSSID set must perform the following:

[0230] - The beacon and probe response frames transmitted by the AP include a BSS Parameters Change Count subfield for each of all APs associated with the same AP MLD as the AP corresponding to the Nontransmitted BSSID.

[0231] The BSS Parameters Change Count subfield value for each AP is initialized to 0 and must be increased by 1 when a significant update occurs to the operational parameters of the corresponding AP (modulo 256 method excluding 255).

[0232] The BSS Parameters Change Count subfield for each of the other AP(s) linked to the AP MLD must be transmitted in the MLD Parameters subfield within the TBTT Information field of the RNR element corresponding to the AP, and each of the other AP(s) is identified by the Link ID subfield of the MLD Parameters subfield.

[0233] The BSS Parameters Change Count subfield for a Nontransmitted BSSID must be transmitted in the Common Info field of the Basic Multi-Link element included within the Nontransmitted BSSID Profile subelement of the Multiple BSSID element (in the case of a probe response frame that is not a multilink probe response). In this case, the AP corresponding to the Nontransmitted BSSID is identified by the Link ID subfield of the Common Info field within the Basic Multi-Link element.

[0234] The BSS Parameters Change Count subfield for the Nontransmitted BSSID must be transmitted in the Common Info field within the Basic Multi-Link element outside the Multiple BSSID element (in the case of a multilink probe response frame). At this time, the AP corresponding to the Nontransmitted BSSID is identified by the Link ID subfield of the Common Info field within the Basic Multi-Link element.

[0235] - If at least one of the following conditions is met, set the Critical Update Flag subfield of the Nontransmitted BSSID Capability field within the Nontransmitted BSSID Capability element (for the Nontransmitted BSSID) in the beacon and probe response frames to 1 until the next DTIM beacon of the Nontransmitted BSSID is included.

[0236] If there is a change in the BSS Parameters Change Count subfield value of the MLD Parameters field within the Reduced Neighbor Report (RNR) element for any AP linked to the same AP MLD as the AP corresponding to the Nontransmitted BSSID, or in the BSS Parameters Change Count subfield value corresponding to the Nontransmitted BSSID within the Common Info field of the Basic Multi-Link element.

[0237] When a new linked AP is added to an AP MLD linked to a Nontransmitted BSSID.

[0238] When a Nontransmitted BSSID Profile corresponding to a Nontransmitted BSSID linked to an AP MLD is modified by including a Reconfiguration Multi-Link element or adding a new Per-STA Profile subelement by a reporting AP.

[0239] If the AP associated with the AP MLD associated with the Nontransmitted BSSID is disabled or enabled via the new advertised TTLM defined in 35.3.7.2.4 (advertised TTLM in beacon and probe response frames). Otherwise, set the Critical Update Flag subfield of the Nontransmitted BSSID Capability field to 0.

[0240] - For each reported AP associated with the same AP MLD as the AP corresponding to the Nontransmitted BSSID, if all updated elements corresponding to the latest critical update that caused a change in the BSS Parameters Change Count value of the reported AP are included in the frame carrying the RNR element, the All Updates Included subfield in the MLD Parameters subfield within the TBTT Information field of the RNR element corresponding to the reported AP is set to 1. This subfield remains at 1 until updated elements are no longer included or the BSS Parameters Change Count subfield is further increased due to another critical update, otherwise it is set to 0.

[0241] - If the Critical Update Flag subfield of the Nontransmitted BSSID Capability field is set to 1 in at least one Nontransmitted BSSID profile included in a Multiple BSSID element within the same frame, the Nontransmitted BSSIDs Critical Update Flag subfield of the Capability Information field is set to 1 in the beacon frames and probe response frames transmitted by the AP. Otherwise, the Nontransmitted BSSIDs Critical Update Flag subfield is set to 0. The flag is set to 1 up to the later DTIM beacon time among the Nontransmitted BSSIDs for which the Critical Update Flag subfield of the Nontransmitted BSSID Capability field is set to 1 (including that time).

[0242] An AP MLD associated with a Nontransmitted BSSID in a set of Multiple BSSIDs must include a BSS Parameters Change Count subfield for each of all APs associated with the corresponding AP MLD and for which (re)association was requested in a received (re)association request frame in the (Re)Association Response frame that it transmits.

[0243] ― The BSS Parameters Change Count subfield for each of the other AP(s) associated with the AP MLD must be transmitted in the STA Info subfield within the Per-STA Profile subelement of the Basic Multi-Link element corresponding to the AP. At this time, each of the other AP(s) is identified by the Link ID subfield within the STA Control field of the Per-STA Profile subelement.

[0244] The BSS Parameters Change Count subfield for the Nontransmitted BSSID must be transmitted in the Common Info field within the Basic Multi-Link element, and the AP corresponding to the Nontransmitted BSSID is identified by the Link ID subfield of the Common Info field within the Basic Multi-Link element.

[0245] In a Multiple BSSID set, the AP corresponding to the Nontransmitted BSSID responds to the (re)connection request frame by transmitting a (re)connection response frame that does not contain a Multiple BSSID element. The Basic Multi-Link element carried in the (re)connection response frame transmitted by the AP associated with the AP MLD carries the information of the corresponding AP MLD and the complete profile of other AP(s) associated with the same MLD.

[0246] The non-AP MLD must record and maintain the most recently received BSS Parameters Change Count subfield value for each connected AP linked to the AP MLD.

[0247] When a non-AP MLD-linked non-AP STA receives a BSS Parameters Change Count subfield for a specific AP, if the AP is linked to the AP MLD that performed the ML configuration with the non-AP MLD and operates on a link that is part of the ML configuration, and the value of the BSS Parameters Change Count subfield for the AP is different from a previously received value, the non-AP MLD must follow one of the following mechanisms.

[0248] ― A non-AP MLD-linked non-AP STA connected to the AP attempts to receive a beacon frame or a probe response frame from the AP. ― Any non-AP STA connected to the non-AP MLD attempts to send a probe request frame to its connected AP, soliciting information about the AP.

[0249] However, if the value of the BSS Parameters Change Count subfield is equal to the value obtained by adding 1 to the latest received value for the corresponding AP recorded by the non-AP MLD, and the All Updates Included subfield in the MLD Parameters subfield within the TBTT Information field of the Reduced Neighbor Report (RNR) element corresponding to the AP is set to 1, then no additional action by the non-AP MLD is required because the updated elements are included in the received frame.

[0250] A probe request frame can be a multilink probe request or a probe request frame that is not a multilink probe request.

[0251] An AP operating on a non-primary link associated with an NSTR (Non-Simultaneous Transmit and Receive) mobile AP MLD does not transmit beacon frames and does not respond to probe request frames. The BSS Parameters Change Count subfield for an AP operating on a non-primary link must be advertised only through the MLD Parameters subfield within the TBTT Information field of the RNR element corresponding to the AP on the primary link.

[0252] Figure 13 shows an example of a critical update procedure in a multi-link environment.

[0253] Referring to FIG. 13, a critical update procedure for AP 2 associated with AP 1 of an AP MLD is described. The Beacon frame / Probe Response frame transmitted by AP 2 may include the following information as critical update occurrence information for AP 1 belonging to the same MLD:

[0254] 1) RNR (Reduced Neighbor Report) IE: For example, the RNR IE may include a Neighbor AP Information field, and the TBTT Information field of the Neighbor AP Information field may include an MLD Parameters subfield.

[0255] Figure 14 shows an example of the MLD Parameters subfield format.

[0256] Referring to FIG. 14, the MLD Parameters subfield may include at least one of the AP MLD ID subfield (8 bits, B0 to B7), Link ID subfield (4 bits, B8 to B11), BSS Parameters Change Count (BPCC) subfield (8 bits, B12 to B19), All Updates Included subfield (1 bit, B20), Disabled Link Indication subfield (1 bit, B21), or Reserved bits (2 bits, B22 to B23). The number of bits and / or bit positions of the subfields exemplified in FIG. 14 are exemplary and may be changed.

[0257] For example, the BPCC for AP 1 can be incremented by 1 whenever a significant update of AP 1 occurs. In Figure 13, the BPCC can be incremented from 5 to 6 at Beacon 22 because the EHT Operation IE of AP 1 was updated in the Beacon frame of AP 1 (e.g., Beacon 12), and the BPCC can be incremented from 6 to 7 at Beacon 23 because the Quiet IE was included in the Beacon frame of AP 1 (e.g., Beacon 13). Therefore, STA 1 connected to AP 2 can know how many significant updates have occurred based on the increment of the BPCC (or, the incremented BPCC / count).

[0258] The All Updates Included subfield indicates whether updated elements corresponding to the latest significant update that caused a change in the BSS Parameters Change Count subfield value of the reported AP are included in the frame carrying the RNR element. The All Updates Included subfield is set to 1 if all updated elements are included, and to 0 otherwise.

[0259] 2) The Critical Update Flag field of the Capability Information field of the Beacon frame / Probe Response frame can be set to 1 when a change occurs in the BPCC of the RNR IE. For example, the Critical Update Flag field is a field intended to prevent the STA from skipping (or passing) the RNR IE and to allow the STA to check the RNR IE. The Critical Update Flag field can be maintained at least from the time a critical update occurs until the next DTIM Beacon so that all STAs can recognize it as much as possible. In FIG. 13, the value of the Critical Update Flag field is maintained at 1 from the time a critical update of AP 1 occurs until Beacon 25, which is the next DTIM Beacon of AP 2.

[0260] 3) When a critical update occurs that includes IEs related to the Channel Switch and / or Quiet of AP 1, AP 2 may include the said IE in the Per-STA Profile subelement corresponding to AP 1 in the Basic Multi-link element (or Basic ML IE). In FIG. 13, when the Quiet IE is included in the Beacon of AP 1, AP 2 may indicate, starting from Beacon 23, that a critical update has occurred due to the inclusion of the Quiet IE for AP 1 based on at least one of the BPCC subfield, the Critical Update Flag subfield, or the All Updates Included subfield. AP 2 may indicate that the IE corresponding to the critical update for AP 1 is included in the Basic ML IE by setting the All Updates Included field corresponding to AP 2 in the RNR IE to 1.

[0261] Meanwhile, at least one feature / mode for subsequent generations, including 802.11bn (or UHR), following 802.11be (or EHT), may also be considered a critical update. However, if the BPCC, Critical Update Flag, and / or All Updates Included fields are reused for 802.11bn feature / modes, 802.11be STAs may not understand or recognize the updates. For example, if a change in the parameters of the UHR feature / mode Dynamic Power Save (DPS) is considered a critical update, 802.11be STAs may not understand or recognize the updates even if the BPCC is incremented and / or set as the Critical Update Flag. Therefore, for critical updates to UHR feature / modes, indicators distinct from 802.11be (e.g., BPCC, Critical Update Flag, and / or All Updates Included fields) may be required.

[0262] In addition, parameters for specific features / modes can be considered as parameters that do not change frequently. For example, if parameters for specific features / modes are included in Beacon / Probe Response frames every cycle, overhead may increase. Basically, currently operating parameters can be recognized using Probe Request / Response and Association Request / Response frames, and in particular, parameters of at least one other AP can also be recognized through Multi-link (ML) probe request / response and multi-link setup defined in 802.11be. Therefore, Beacon overhead can be reduced by considering specific parameters as targets for critical updates and notifying only when these parameters are added, modified, or changed. The present disclosure provides a method and apparatus for critical updates that address the problem of increased Beacon overhead.

[0263] Meanwhile, important updates related to NPCA may occur. For example, if at least one condition (or field / element / parameter) related to NPCA is updated or changed in a Beacon or Probe Response frame (i.e., if an important update related to NPCA occurs), the AP MLD needs to notify the non-AP MLD of these updates or changes.

[0264] Accordingly, the present disclosure provides various embodiments regarding important updates related to the NPCA.

[0265] In the present disclosure, the term refers to an AP that transmits elements such as a Neighbor Report element, a Reduced Neighbor Report element, or a Basic Multi-Link element related to a reporting AP and a reported AP.

[0266] In the present disclosure, the AP to be reported refers to an AP identified in an element such as a Neighbor Report element or a Reduced Neighbor Report element, or an AP identified in the Per-STA Profile subelement of a Basic Multi-Link element.

[0267] In the present disclosure, fields and subfields may be used interchangeably.

[0268] In the present disclosure, “X field / subfield” may include “X information / X” and may be used interchangeably with “X information / X”.

[0269] In the present disclosure, element and IE (information element) may be used interchangeably.

[0270] Designations (names) in this disclosure may be changed, and STA may include AP STA and / or non-AP STA. In this disclosure, Resource Unit (RU) may be RU or Multiple RU (MRU).

[0271] FIG. 15 illustrates an example of a method performed by AP for an important update related to NPCA according to various embodiments of the present disclosure.

[0272] Referring to FIG. 15, in step 1501, AP can set at least one of the critical update flag (or UCUF / UHR CUF / Enhanced CUF) or BSS parameter change count (or UHR BPCC / Enhanced BPCC) fields to a corresponding value based on the existence of updates to one or more parameters for NPCA.

[0273] In step S1503, the AP may transmit a frame containing at least one of a critical update flag or a BSS parameter change count field. The frame may contain a parameter update element. The parameter update element may contain one or more parameters for the NPCA.

[0274] According to various embodiments, one or more parameters for NPCA may include at least one of information about the NPCA primary channel, information about the NPCA switching delay, information about the NPCA switching back delay, information about the NPCA minimum duration threshold, information about the NPCA disabled subchannel bitmap, information about whether the NPCA operation is enabled, information about the TB (trigger-based) mode, information about the NPCA mode, or information about the effective time.

[0275] According to various embodiments, the valid time may include the time during which one or more parameters for the NPCA are applied after the frame is transmitted.

[0276] According to various embodiments, one or more parameters for NPCA may be applied after the frame is transmitted and after one or more TBTTs (target beacon transmission times). Information regarding the validity time may indicate the number of the one or more TBTTs.

[0277] According to various embodiments, the effective time may be indicated based on a time synchronization function (TSF) or a partial TSF.

[0278] According to various embodiments, the parameter update element may include one or more other parameters for an NPCA for which no update exists. One or more parameters for an NPCA for which an update exists may be set to an updated value relative to a previous value. One or more other parameters for an NPCA for which no update exists may be set to a value identical to the previous value.

[0279] According to various embodiments, one or more other parameters for an NPCA for which no update exists may be excluded from the parameter update element. For each of the one or more parameters for an NPCA for which an update exists, the parameter update element may further include at least one of: type information; an ID (identifier) ​​value; or information regarding the length of the corresponding field.

[0280] According to various embodiments, based on the existence of updates to one or more parameters for NPCA: the critical update flag is set to 1; and the value of the BSS parameter change count field can be increased by 1.

[0281] According to various embodiments, a critical update flag may be included in the capability information field of the frame.

[0282] According to various embodiments, the BSS parameter change count field may be included in the TBTT (target beacon transmission time) information field in the reduced neighbor report element of the frame.

[0283] According to various embodiments, the BSS parameter change count field may be included in the common information field in the basic multi-link element of the frame.

[0284] According to various embodiments, the presence bitmap field of a basic multi-link element may include information regarding whether a BSS parameter change count field exists in the common information field of the basic multi-link element.

[0285] According to various embodiments, the BSS parameter change count field may be included in the STA (station) information field in the basic multi-link element of the frame.

[0286] According to various embodiments, the STA control field in the basic multi-link element may include information regarding whether a BSS parameter change count field exists in the STA information field of the basic multi-link element.

[0287] According to various embodiments, the parameter update element may include a field related to a mode. Based on the value of the field related to the mode being a value related to NPCA, the parameter update element may include one or more parameters for NPCA.

[0288] According to various embodiments, the parameter update element may be included in a per-STA profile corresponding to the affected AP associated with the update in a basic multi-link element.

[0289] According to various embodiments, the parameter update element may include delivery traffic indication map (DTIM) beacons after the time the update occurred.

[0290] According to various embodiments, the frame may be a beacon frame, a probe response frame, a connection response frame, a reconnection response frame, or a link reset response frame.

[0291] FIG. 16 illustrates an example of signal flow between an AP MLD and a non-AP MLD for important updates related to NPCA according to various embodiments of the present disclosure.

[0292] Referring to FIG. 16, in step S1601, AP can set at least one of the fields of the important update flag (or UCUF / UHR CUF / Enhanced CUF) or the BSS parameter change count (or UHR BPCC / Enhanced BPCC) to a corresponding value based on the existence of updates to one or more parameters for NPCA.

[0293] In step S1603, the AP may transmit a frame containing at least one of a critical update flag or a BSS parameter change count field. The STA may receive a frame containing at least one of a critical update flag or a BSS parameter change count field.

[0294] In step S1605, the STA may obtain a parameter update element from the frame based on at least one of a critical update flag or a BSS parameter change count field. The parameter update element may include one or more parameters for the NPCA.

[0295] Below, a detailed implementation of important updates related to NPCA is described.

[0296] 1. Critical Update Flag (CUF)

[0297] A Critical Update Flag may be defined for at least one subsequent generation, including 802.11be (or EHT) and 802.11bn (or UHR). For example, a change in the Critical Update Flag value may indicate that the BPCC for a feature / mode of the corresponding generation, which is the target of the critical update, has changed. Additionally, the Critical Update Flag may be applied at the MLD-level. For example, a change in the Critical Update Flag value may occur if the BPCC for at least one STA belonging to the MLD changes.

[0298] 1) In some implementations, a Unified Critical Update Flag (UCUF) field may be added using the reserved bit(s) of the Capability Information field (e.g., B2, B3, B14, B15) or the reserved bit(s) of the Extended Capabilities field of the Extended Capabilities element (e.g., B4-B6, B41-43, B111~). The size of the UCUF field may be X bits (e.g., X = 2, 3, 4), and the value of the UCUF field may indicate that a critical update has occurred for a feature / mode of a specific generation. For example, when X = 2 bits, the values ​​of the UCUF and EHT CUF may be interpreted as shown in Table 1 below. In this disclosure, “Next UHR” may mean a generation after the UHR.

[0299] UCUFEHT CUF Description of the generation where a significant update occurred 00Nothing No significant updates occurred 01EHTEHT Understandable by STA 10Only UHRUHR Understandable by STA 11UHR and EHTUHR Significant updates occurred for feature / mode and EHT feature / mode. That is, the former is understandable by UHR STA, and the latter by EHT STA 20Only Next UHRNext Understandable by UHR STA 21EHT and only Next UHRNext Significant updates occurred for UHR feature / mode and EHT feature / mode. That is, the former is understandable by Next UHR STA, and the latter by EHT STA… … … …

[0300] In Table 1, UCUF is shown only up to 2, but the same applies to cases where the UCUF value is greater than 2. When the UCUF value is greater than or equal to 1 (i.e., when significant updates have occurred for feature / modes in two or more generations among UHR and subsequent generations), at least one of the following methods may be applied:

[0301] A. The value of UCUF can be set to the value corresponding to the lowest Generation. For example, if a significant update occurs simultaneously for Next UHR feature / mode and UHR feature / mode, UCUF can be set to 1, which is the value corresponding to UHR (i.e., UCUF = 1). In this case, Next UHR STA can recognize and check that a significant update corresponding to Next UHR feature / mode may have occurred.

[0302] B. When the value of UCUF is 2 or greater, STAs of generations prior to the generation corresponding to the UCUF value can understand this UCUF and recognize and confirm that significant updates to the feature / mode of that generation may have occurred. For example, when UCUF = 2, UHR STAs can recognize and confirm that significant updates to the UHR feature / mode may have occurred.

[0303] 2) In some implementations, a 1-bit CUF for a new generation may be added whenever a new generation is introduced, using the reserved bit(s) of the Capability Information field (e.g., B2, B3, B14, B15) or the reserved bit(s) of the Extended Capabilities field of the Extended Capabilities element (e.g., B4-B6, B41-43, B111~). For example, a UHR CUF may be included / added for the UHR, and a separate Next UHR CUF may be included / added for the Next UHR. As each CUF is configured, the value of each CUF may be interpreted as shown in Table 2 below.

[0304] EHT CUFUHR CUFNext UHR CUF Description of generation where significant updates occurred 000Nothing No significant updates occurred 100EHTEHT Understandable by STA 010Only UHRUHR Understandable by STA 001Only Next UHRN Ext UHR Understandable by STA 110UHR and EHTUHR feature / mode and EHT feature / mode significant updates occurred. That is, the former is understandable by UHR STA, and the latter by EHT STA 101Next UHR and EHT Next UHR feature / mode and EHT feature / mode significant updates occurred. That is, the former is understandable by UHR STA, and the latter by EHT STA 111Next UHR and UHR and EHT Next UHR feature / mode, UHR feature / mode, and EHT feature / mode significant updates occurred. In other words, it can be understood that the first is the Next UHR STA, the second is the UHR STA, and the third is the EHT STA… … … … …

[0305] In Table 2, examples are given only up to the Next UHR CUF, but the same can be applied to CUFs of subsequent generations.

[0306] 2. BSS Parameters Change Count (BPCC)

[0307] The value of UCUF and / or CUF for each generation can be set to 1 based on BPCC changes. However, in Basic Multi-link IE and / or RNR IE, if the BPCC for EHT changes based on significant updates to UHR feature / mode, the EHT STA may not understand this. Therefore, a separate BPCC for UHR (or Next UHR) may be required.

[0308] In the present disclosure, a reporting AP may transmit a changed BPCC, and a reported AP may be an AP corresponding to the changed BPCC (e.g., an AP receiving parameters associated with the changed BPCC). In the present disclosure, BPCCs for a UHR are described, but BPCCs may be included in the same way for subsequent generations / Next UHRs.

[0309] A separate BPCC for UHR (or Next UHR) may be included in the following ways.

[0310] (1) Addition / inclusion of BPCC for each generation

[0311] A. UHR BPCC corresponding to Reporting AP

[0312] For example, the UHR BPCC corresponding to the Reporting AP can be included in the Basic ML IE.

[0313] Figure 17 shows an example where the UHR BPCC corresponding to the Reporting AP is included in the Common Info field of the Basic ML IE.

[0314] Referring to FIG. 17, a UHR BPCC may be added to the Common Info field of the Basic ML IE for cases where a significant update occurs for the reporting AP transmitting this Basic ML IE. For example, the reserve bits (e.g., B7, B8) of the Presence Bitmap field may be used to add or include the UHR BSS Parameters Change Count Present field. The UHR BSS Parameters Change Count Present field may indicate whether the UHR BSS Parameters Change Count field (e.g., 1 octet) exists in the Common Info field.

[0315] Additionally or alternatively, the value of the UHR BSS Parameter Change Count field can have various sizes (e.g., 4 bits, 6 bits) considering the maximum value of UHR BPCC.

[0316] Figure 18 shows an example of the Presence Bitmap field format of Basic ML IE including UHR BPCC.

[0317] Referring to FIG. 18, the Presence Bitmap field of the Basic ML IE may include a UHR BSS Parameter Change Count field. For example, a Reporting AP may include the UHR BSS Parameter Change Count field in the Presence Bitmap field of the Basic ML IE and transmit it. The value of the UHR BSS Parameter Change Count field may have a value of various sizes (e.g., 2 bits, 3 bits, 4 bits) by utilizing at least one of the reserved bits (e.g., B7 to B11).

[0318] Additionally or alternatively, the UHR BSS Parameter Change Count field may have various sizes (e.g., 1 octet) considering the maximum value of the UHR BSS Parameter Change Count field.

[0319] Additionally or alternatively, the Reporting AP may include a UHR BSS Parameters Change Count field (e.g., 1 octet) in the Per-STA Profile subelement of the Link Info field containing the link ID corresponding to the reporting AP in Basic ML IE.

[0320] Figure 19 shows an example where the UHR BPCC corresponding to the Reporting AP is included in the Link Info field of the Basic ML IE.

[0321] Referring to FIG. 19, the UHR BSS Parameters Change Count field may be included in the STA Info field or the STA Profile field. The STA Control field may include the UHR BSS Parameters Change Count Present field, and the UHR BSS Parameters Change Count Present field may indicate whether the UHR BSS Parameters Change Count field exists in the STA Info field or the STA Profile field.

[0322] Figure 20 shows an example of the STA Control field format of Basic ML IE including UHR BPCC.

[0323] Referring to FIG. 20, the Reporting AP can transmit the UHR BSS Parameters Change Count field by including it in the STA Control field of the Per-STA Profile, which contains the Link ID corresponding to the Reporting AP in the Link Info field of the Basic ML IE. The value of the UHR BSS Parameter Change Count field can have a value of various sizes (e.g., 2 bits, 3 bits, 4 bits) by utilizing at least one of the reserved bits (e.g., B7 to B11).

[0324] Additionally or alternatively, the UHR BSS Parameter Change Count field may have various sizes (e.g., 1 octet) considering the maximum value of the UHR BSS Parameter Change Count field.

[0325] B. UHR BPCC corresponding to Reported AP

[0326] For example, the Reporting AP may include a UHR BSS Parameters Change Count field (e.g., 1 octet) in the TBTT Information field corresponding to the reported AP.

[0327] Additionally or alternatively, the value of the UHR BSS Parameter Change Count field can have various sizes (e.g., 4 bits, 6 bits) considering the maximum value of UHR BPCC.

[0328] Figure 21 shows an example of a TBTT Information field format including a UHR BPCC corresponding to a Reported AP.

[0329] Referring to FIG. 21, the TBTT Information field may include a UHR BSS Parameters Change Count Present field corresponding to a reported AP. For example, the UHR BSS Parameters Change Count Present field corresponding to a reported AP may be included in the UHR Parameters field of the TBTT Information field. When all fields of the TBTT Information field are included, the length of the TBTT Information field may be 18 octets or more.

[0330] Additionally or alternatively, the Reporting AP may include a UHR BSS Parameters Change Count field (e.g., 1 octet) in the Per-STA Profile subelement of the Link Info field, which contains the link ID corresponding to the AP reported to the Basic ML IE.

[0331] Figure 22 shows an example of a Basic ML IE format containing a UHR BPCC corresponding to a Reported AP.

[0332] Referring to FIG. 22, the UHR BSS Parameters Change Count field may be included in the STA Info field or the STA Profile field. The STA Control field may include the UHR BSS Parameters Change Count Present field, and the UHR BSS Parameters Change Count Present field may indicate whether the UHR BSS Parameters Change Count field exists in the STA Info field or the STA Profile field.

[0333] Figure 23 shows an example where UHR BPCC is included in the STA Control field corresponding to the Reported AP.

[0334] Referring to FIG. 23, the Reporting AP can transmit the UHR BSS Parameters Change Count field by including it in the STA Control field of the Per-STA Profile, which contains the Link ID corresponding to the Reported AP in the Link Info field of the Basic ML IE. For example, if the UHR BSS Parameter Change Count field is included in the STA Control field, the Basic ML IE containing such STA Control field may be included in a (Re)Association Response frame, a Link Reconfiguration Response frame, etc. The value of the UHR BSS Parameter Change Count field can have a value of various sizes (e.g., 2 bits, 3 bits, 4 bits) by utilizing at least one of the reserved bits (e.g., B7 to B11).

[0335] Additionally or alternatively, the UHR BSS Parameter Change Count field may have various sizes (e.g., 1 octet) considering the maximum value of the UHR BSS Parameter Change Count field.

[0336] Additionally or alternatively, the UHR BPCC field and / or the Presence bit for the UHR BPCC field may be indicated via a separate IE included in a Beacon, Probe Response frame, or a separate Action frame. In this case, a link ID corresponding to each Reporting or Reported AP may be included in the corresponding frame / IE.

[0337] The initial value of the aforementioned BPCCs may be 0, and the value of BPCC may be increased by 1 each time a critical update occurs. Additionally or alternatively, the value of BPCC may be increased by 1 for each IE for which a critical update occurs. For example, if a critical update occurs for 2 IEs, the value of BPCC may be increased by 2.

[0338] 3. Parameter Update Procedure

[0339] Below, a method for indicating parameters that are updated based on important updates related to the aforementioned UCUF, UHR CUF and / or UHR BPCC through (fields and / or IE) is described.

[0340] When a critical update occurs (e.g., a BPCC change / Critical Update Flag setting), the associated updated UHR parameters (Updated UHR Parameters, or Updated Parameters) may be indicated based on at least one of the following methods. For example, when an NPCA parameter for an NPCA operation is updated, the NPCA parameter may include at least one field described below.

[0341] Additionally or alternatively, the NPCA parameters described below can be initially set using a significant update.

[0342] For example, NPCA parameters may include at least one of the following:

[0343] -NPCA Enabled: The NPCA Enabled field indicates whether the STA transmitting the NPCA Enabled field has enabled NPCA operation. The NPCA Enabled field can have a value of 1 bit. If the value of the NPCA Enabled field is 1, it may indicate that NPCA operation is enabled. If the value of the NPCA Enabled field is 0, it may indicate that NPCA operation is disabled.

[0344] Based on the NPCA Enabled field that is updated via a critical update method, in situations where the AP does not perform NPCA operations, only non-AP STAs can trigger NPCA operations to perform unnecessary switching to the NPCA Primary channel and / or prevent NPCA operations from being performed.

[0345] -NPCA primary channel: The NPCA primary channel field indicates the number of a channel (e.g., a 20 MHz channel) within the AP's BSS bandwidth that STAs switch to in order to perform NPCA operations. For example, if the size of the NPCA primary channel field is 8 bits, a value of 36 in the NPCA primary channel field may indicate that the 20 MHz channel with channel number 36 is the NPCA primary channel.

[0346] Additionally or alternatively, the channel number can be set based on Country elements and action classes as shown in FIG. 24.

[0347] Figure 24 shows an example of operation classes for channel numbers.

[0348] For example, among the 20MHz channels, the 20MHz channel with channel number 36 can be determined as the NPCA primary channel.

[0349] Additionally or alternatively, the NPCA primary channel field may have a bitmap format. For example, if the NPCA primary channel field is represented as an 8-bit bitmap, and each bit of the bitmap corresponds to a 20 MHz channel in order from the lowest frequency to the highest frequency, the bitmap “0000 0001” may indicate that the last 20 MHz channel is the NPCA primary channel for an AP operating at 160 MHz.

[0350] As another example, the NPCA primary channel field can be represented as a 16-bit bitmap.

[0351] Additionally or alternatively, if the NPCA primary channel is determined within the AP's secondary (BSS operation BW / 2) MHz, an 8-bit bitmap may indicate the NPCA primary channel with a maximum BSS operation BW of 320 MHz. For example, if the 8-bit bitmap is represented as 0000 0001, this may indicate that for an AP with a BSS operation BW of 320 MHz, the highest frequency 20 MHz channel among the 20 MHz channels ranging from the lowest frequency to the highest frequency within the secondary 160 MHz is the NPCA primary channel.

[0352] Based on the NPCA primary channel field that is updated via a critical update method, non-AP STAs can perform preamble detection based on the NPCA primary channel that the AP will use when the NPCA operation is triggered, and can successfully receive frames transmitted by the AP during the NPCA operation.

[0353] -NPCA Switching Delay: The NPCA Switching Delay field represents the time it takes for an NPCA STA to switch from a BSS primary channel to an NPCA primary channel. For example, if the unit of the NPCA Switching Delay is 4us and the size of the NPCA Switching Delay field is 8 bits, a value of 2 in the NPCA Switching Delay field may indicate that an NPCA Switching Delay of 8us occurs.

[0354] Based on the NPCA transition delay field, which is updated via a critical update method, NPCA STAs can guarantee that peer STAs have completed transitioning to the NPCA primary channel and start frame exchange. Therefore, it is possible to prevent unnecessary frame exchange with peer STAs that have not completed transitioning to the NPCA primary channel.

[0355] - NPCA Switching Back Delay: The NPCA Switching Back Delay field represents the time it takes for an NPCA STA to switch from the NPCA primary channel to the BSS primary channel. For example, if the unit of the NPCA Switching Back Delay is 4us and the size of the NPCA Switching Back Delay field is 8 bits, a value of 2 in the NPCA Switching Back Delay field may indicate that an NPCA Switching Back Delay of 8us occurs.

[0356] Additionally or alternatively, the NPCA transition delay field and the NPCA transition return delay field may have a size of 6 bits and can be encoded as shown in Table 3 below:

[0357] NPCA Transition Delay Subfield Value / NPCA Transition Return Delay Subfield Value NPCA Transition Delay / NPCA Transition Return Delay 00 us132 us264 us3128 us4256 us5512 us61024 us7-63Reserved

[0358] - NPCA Minimum Duration Threshold: The NPCA Minimum Duration Threshold field represents the minimum time required to perform an NPCA operation. For example, if inter-BSS activity (e.g., inter-BSS PPDU and / or inter-BSS TXOP (transmission opportunity)) is detected on the BSS primary channel, and the duration of such activity detection on the BSS primary channel is shorter than the NPCA Minimum Duration Threshold, the STAs may not switch to the NPCA primary channel and may not perform an NPCA operation. For example, the size of the NPCA Minimum Duration Threshold field may be 7 bits. In this case, B0 of the NPCA Minimum Duration Threshold field may indicate a unit time, and the values ​​of the remaining B1 through B7 may be used to represent the NPCA Minimum Duration Threshold.

[0359] For example, if B0 = 0, the unit time is 8us, and the NPCA minimum duration threshold can be 8*(values ​​expressed as B1 to B7)us. For example, if the NPCA minimum duration threshold field is expressed as 000 0010, the NPCA minimum duration threshold can be 8*2=16us.

[0360] For example, if B0 = 1, the unit time is 128us, and the NPCA minimum duration threshold can be 128*(values ​​expressed as B1 to B7)+512us. For example, if the NPCA minimum duration threshold field is expressed as 100 0010, the NPCA minimum duration threshold can be 128*2+512=768us.

[0361] Additionally or alternatively, the NPCA minimum period threshold field may have a size of 2 octets and may represent NPCA minimum period thresholds in the range of 0 to 32767 us.

[0362] Additionally or alternatively, the NPCA minimum period threshold field can have a size of 6 bits and can be encoded as shown in Table 4 below:

[0363] NPCA Minimum Period Threshold Subfield Value NPCA Minimum Period Threshold 00 us 132 us 264 us 3128 us 4256 us 5512 us 61,024 us 72,048 us 84,096 us 98,192 us 1016,384 us… … 30-63 Reserved

[0364] Additionally or alternatively, NPCA minimum period thresholds may be defined according to the NPCA modes described below. For example, PPDU_NPCA minimum period threshold field and TXOP_NPCA minimum period threshold field may be defined. These NPCA minimum period threshold fields may also have NPCA minimum period threshold values ​​according to Table 4. Based on the NPCA minimum period threshold fields that are updated via a critical update method, NPCA STAs can identify whether the corresponding NPCA operation period is a time when frame switching can be performed when NPCA is triggered. Thus, unnecessary switching to the NPCA primary channel, which may result in power consumption, can be prevented.

[0365] - NPCA Disabled Subchannel Bitmap: A bitmap indicating the subchannels to be punctured when the NPCA STA operates on the NPCA primary channel. Each bit of the NPCA Disabled Subchannel Bitmap can be associated with a corresponding 20 MHz subchannel in order from the lowest frequency to the highest frequency. For example, if the NPCA Disabled Subchannel Bitmap has a size of 8 bits and is represented as 0000 0011, this may indicate that the last two 20 MHz subchannels are punctured.

[0366] Based on the NPCA inactive subchannel bitmap field, which is updated via a critical update method, non-AP STAs can utilize channels excluding those with high interference.

[0367] -TB (trigger-based) mode: Indicates whether to operate in trigger-only mode or allow untriggered mode when performing an NPCA operation. For example, the size of the TB mode field may be 2 bits. A value of 0 in the TB mode field indicates that untriggered mode is allowed and / or that a non-AP STA can be the TXOP holder. A value of 1 in the TB mode field indicates that it operates in trigger-only mode and that only the AP can be the TXOP holder when performing an NPCA operation. A value of 2 in the TB mode field indicates that only the first TXOP in the NPCA operation operates in trigger-only mode.

[0368] Based on the TB mode field that is updated via a critical update method, if there are many non-AP STAs performing NPCA operations within the BSS, they may be restricted to performing only trigger-based UL. This prevents frame collisions caused by multiple STAs transmitting frames simultaneously and allows the AP to manage the STAs.

[0369] -NPCA Mode: Can indicate whether the NPCA operation is PPDU-based or TXOP-based. For example, the size of the NPCA mode field can be 1 bit. If the value of the NPCA mode field is 0, it indicates that the NPCA operation is performed PPDU-based until the inter-BSS TXOP is terminated. If the value of the NPCA mode field is 1, it indicates that the NPCA operation is performed TXOP-based until the inter-BSS TXOP is terminated. In other words, the NPCA mode field can indicate whether the duration of the NPCA operation is set based on OBSS PPDU or based on TXOP.

[0370] Based on the NPCA mode field that is updated as a critical update method, for example, if PPDU-based NPCA operation is allowed, it is possible to prevent a situation where medium sync is lost when switching back to the primary channel after completing the NPCA operation.

[0371] - Effective Time: This may indicate the time when the various NPCA parameters described above (e.g., NPCA primary channel, NPCA switching delay, NPCA switching return delay) are actually applied. For example, if the Effective Time field has a size of 8 bits, a value of 0 in the Effective Time field may indicate that the NPCA parameter can be applied at any point after the frame containing the NPCA parameter is transmitted. A value of 1 in the Effective Time field may indicate that the NPCA parameter can be applied after the next TBTT (or, the first TBTT) and / or from the time including it after the frame containing the NPCA parameter is transmitted. A value of 2 in the Effective Time field may indicate that the NPCA parameter can be applied after the next-next TBTT (or, the second TBTT) and / or from the time including it after the frame containing the NPCA parameter is transmitted.

[0372] Additionally or alternatively, the validity time can be indicated based on the TSF. For example, a TSF based on the entire Timestamp (e.g., an octet) or a TSF based on a part (i.e., a partial TSF) can be used. In the case of a partial TSF, similar to a broadcast TWT, it can be used starting from a specific bit of the TSF up to a bit value of X octets.

[0373] Based on the valid time field that is updated via a critical update method, all STAs performing NPCA operations within the BSS can apply the updated NPCA parameters from the same point in time. Through this, synchronization of NPCA operation-related parameters between the AP and the STAs is possible.

[0374] A. Update parameters corresponding to the Reporting AP

[0375] In the present disclosure, a Parameters Update field / element is defined. The Parameters Update field / element may include at least one of an Updated Parameters Presence Bitmap field or an Updated Parameters field.

[0376] Figure 25 shows an example of the Parameters Update field / element format.

[0377] Referring to FIG. 25, the Updated Parameters Presence Bitmap field may include the UHR Feature / Mode #1 Parameters Present field, the UHR Feature / Mode #2 Parameters Present field, … the UHR Feature / Mode #N Parameters Present field. The Updated Parameters field may include the Updated Parameters For #1 field, the Updated Parameters For #2 field, … the Updated Parameters For #N field. The Updated Parameters Presence Bitmap field includes the Updated Parameters For #K field (1) where a significant update occurred. K Can indicate N). For example, the UHR Feature / Mode #K Parameters Present field (1 K N) can indicate whether the Updated Parameters For #K field exists. For example, if the UHR Feature / Mode #K Parameters Present field is set to 1, it can indicate that the Updated Parameters For #K field exists. If the UHR Feature / Mode #K Parameters Present field is set to 0, it can indicate that the Updated Parameters For #K field does not exist. The Parameters Update field / element can be transmitted by being included in the UHR Operation element of a Beacon, Probe Response frame, or Action frame, or in a separate IE.

[0378] Figure 26 shows examples of UHR Feature / Modes included in the Parameters Update field / element.

[0379] Referring to FIG. 26, UHR Feature / Modes may include NPCA and DPS (dynamic power saving). FIG. 26 illustrates NPCA and DPS as UHR Feature / Modes, but UHR Feature / Modes are not limited thereto. For example, UHR Feature / Modes may include the UHR Feature / Modes exemplified in Table 6 below.

[0380] The Updated Parameters Presence Bitmap field may include the NPCA Parameters Present field and the DPS Parameters Present field. The Updated Parameters field may include the Updated Parameters For NPCA field and the Updated Parameters For DPS field. The Updated Parameters Presence Bitmap field may indicate the Updated Parameters where a significant update occurred.

[0381] For example, the NPCA Parameters Present field can indicate whether the Updated Parameters For NPCA field exists. If the value of the NPCA Parameters Present field is set to 1, it can indicate that the Updated Parameters For NPCA field exists. If the value of the NPCA Parameters Present field is set to 0, it can indicate that the Updated Parameters For NPCA field does not exist.

[0382] For example, the DPS Parameters Present field can indicate whether the Updated Parameters For DPS field exists. If the value of the DPS Parameters Present field is set to 1, it can indicate that the Updated Parameters For DPS field exists. If the value of the DPS Parameters Present field is set to 0, it can indicate that the Updated Parameters For DPS field does not exist.

[0383] For example, the Updated Parameters For NPCA field may include at least one of the above-described NPCA parameters (e.g., NPCA Primary Channel, NPCA Switching Delay, NPCA Switching Back Delay).

[0384] The Parameters Update field / element can be transmitted by being included in the UHR Operation element of a Beacon, Probe Response frame, or Action frame, or in a separate IE.

[0385] Additionally or alternatively, the Parameters Update Present field may be defined as shown in FIG. 27.

[0386] Figure 27 shows an example of a case where the Parameters Update field / element is indicated based on the Parameters Update Present field.

[0387] Referring to FIG. 27, to prevent the Updated Parameters Presence Bitmap field from always being included, the Parameters Update Present field may be included. Based on the Parameters Update Present field, the Parameters Update field / element may be included only when a significant update occurs.

[0388] Figure 28 shows examples of UHR Feature / Modes included in the Parameters Update field / element indicated based on the Parameters Update Present field.

[0389] Referring to FIG. 28, to prevent the Updated Parameters Presence Bitmap field from always being included, the Parameters Update Present field may be included. Based on the Parameters Update Present field, the Parameters Update field / element may be included only when a significant update occurs. For example, when the Parameters Update field / element is included, the Updated Parameters Presence Bitmap field of the Parameters Update field / element may include the NPCA Parameters Present field and the DPS Parameters Present field. The Updated Parameters field of the Parameters Update field / element may include the Updated Parameters For NPCA field and the Updated Parameters For DPS field. The Updated Parameters For NPCA field may include at least one of the above-described NPCA parameters (e.g., NPCA Primary Channel, NPCA Switching Delay, NPCA Switching Back Delay).

[0390] Additionally or alternatively, the Parameters Update field / element can be included in Basic ML IE.

[0391] In some implementations, the Parameters Update field / element may be included in the Common Info field of Basic ML IE. In this case, the Parameters Update Present field and / or the Updated Parameters Presence Bitmap field may be included in the Presence Bitmap field of Basic ML IE. For example, the Parameters Update field / element may be included in the Common Info field of Basic ML IE based on the Parameters Update Present field. For example, the Updated Parameters field may be included in the Common Info field of Basic ML IE based on the Updated Parameters Presence Bitmap field.

[0392] In some implementations, the Parameters Update field / element may be included in the Per-STA Profile subelement containing the link ID corresponding to the Reporting AP in the Link Info field of Basic ML IE.

[0393] Figure 29 shows an example where the Parameters Update field / element is included in the Link Info field.

[0394] Referring to FIG. 29, the Parameters Update field / element may be included in the STA Info field or STA Profile field of the Per-STA Profile subelement, which includes a link ID corresponding to the Reporting AP in the Link Info field. FIG. 29 illustrates a case where the Parameters Update field / element includes the NPCA Parameters Present field and / or the Updated Parameters for NPCA field, in which case the Parameters Update field / element may be referred to as the NPCA Parameters Update field / element.

[0395] The STA Control field may include a Parameters Update Present field, and the Parameters Update Present field may indicate whether a Parameters Update field / element (or, NPCA Parameters Update field / element) exists in the STA Info field or the STA Profile field. Additionally or alternatively, the STA may recognize whether a Parameters Update field / element (or, NPCA Parameters Update field / element) exists in the STA Info field or the STA Profile field based on identifying changes in the BPCC and / or CUF corresponding to the Reporting AP.

[0396] Additionally or alternatively, the Updated Parameters may be transmitted by time T, included in the UHR Operation element of a Beacon, Probe Response frame, or Action frame, or in a separate IE, based on at least one of the following conditions:

[0397] 1) T = Next DTIM Beacon: The corresponding Updated Parameters can be transmitted until the next DTIM Beacon of the Reporting AP.

[0398] 2) T depending on parameter: T may vary depending on the time at which parameters are applied for each feature / mode for the Reporting AP. For example, if the Updated Parameters field of each Feature / Mode contains information about the time at which the Updated Parameters are applied (e.g., based on TBTT or TSF), the Updated Parameters may be transmitted up to that time even if the Next DTIM has passed.

[0399] Additionally or alternatively, if Updated Parameters corresponding to the Reporting AP are included in a frame (e.g., Beacon, Probe Response frame, or Action frame), Updated Parameters Included (e.g., 1 bit) may be indicated in the Common Info of the frame. An STA receiving the frame may recognize that Updated Parameters are included in the frame based on Updated Parameters Included.

[0400] B. Update parameters corresponding to the reported AP

[0401] For example, in Basic ML IE, the Per-STA Profile subelement containing the link ID corresponding to the Reported AP may include a Parameters Update field / element.

[0402] Figure 30 shows an example where the Parameters Update field / element corresponding to the Reported AP is included in the Link Info field.

[0403] Referring to FIG. 30, the Parameters Update field / element corresponding to the Reported AP may be included in the STA Info field or STA Profile field of the Per-STA Profile subelement, which includes the link ID corresponding to the Reported AP in the Link Info field. FIG. 30 illustrates a case where the Parameters Update field / element includes the NPCA Parameters Present field and / or the Updated Parameters for NPCA field, in which case the Parameters Update field / element may be referred to as the NPCA Parameters Update field / element.

[0404] The STA Control field of the corresponding Per-STA Profile subelement may include a Parameters Update Present field, and the Parameters Update Present field may indicate whether a Parameters Update field / element (or, NPCA Parameters Update field / element) exists in the STA Info field or the STA Profile field. Additionally or alternatively, the STA may recognize whether a Parameters Update field / element (or, NPCA Parameters Update field / element) exists in the STA Info field or the STA Profile field based on identifying changes in the BPCC and / or CUF corresponding to the Reported AP.

[0405] Additionally or alternatively, if the Parameters Update field / element (or Updated Parameters field) corresponding to the Reported AP is included, the All Updates Included field of the RNR IE corresponding to the Reported AP may be set to 1.

[0406] Additionally or alternatively, if a Parameters Update field / element (or Updated Parameters field) corresponding to the Reported AP is included, a separate All Updates Included field for the UHR feature / mode may be additionally included to distinguish it from the EHT. For example, the All Updates Included field may be indicated / included by utilizing the reserve bits (e.g., B22, B23) of the MLD Parameters field of the TBTT Information field. Additionally or alternatively, the All Updates Included field may be additionally indicated / included together with the aforementioned UHR BPCC field (utilizing the reserve bits (e.g., B22, B23) of the MLD Parameters field of the TBTT Information field).

[0407] Additionally or alternatively, the Updated Parameters may be transmitted by time T, included in the UHR Operation element of a Beacon, Probe Response frame, or Action frame, or in a separate IE, based on at least one of the following conditions:

[0408] 1) T = Next DTIM Beacon: The corresponding Updated Parameters can be transmitted to the next DTIM Beacon of the Reporting AP (or Reported AP).

[0409] 2) T depending on parameter: T may vary depending on the time at which parameters are applied for each feature / mode for the Reported AP. For example, if the Updated Parameters field of each Feature / Mode contains information about the time at which the Updated Parameters are applied (e.g., based on TBTT or TSF), the Updated Parameters may be transmitted up to that time even if the Next DTIM has passed.

[0410] In the parameter updates corresponding to A. Reporting AP and B. Reported AP described above, the Updated Parameters for NPCA field may be included in the following manner:

[0411] 1) When each field is defined at a fixed location

[0412] Figure 31 shows an example where each field included in the Updated Parameters for NPCA field is defined at a fixed position.

[0413] Referring to FIG. 31, the fields included in the Updated Parameters for NPCA field can be indicated at fixed locations. For example, the NPCA Primary Channel field, NPCA Switching Delay field, and NPCA Switching Back Delay field included in the Updated Parameters for NPCA field each have a size of 1 octet and can be defined / indicated at locations such as those exemplified in FIG. 31. An STA transmitting a frame containing such an Updated Parameters for NPCA field may indicate by updating only the values ​​of the fields related to the parameters to be updated, and may indicate by setting the values ​​of fields not related to the update to be the same as the previous values. STAs receiving a frame containing such an Updated Parameters for NPCA field may consider the parameter related to the field to be updated if the value of the field in the Updated Parameters for NPCA field is different from the most recently received value and update it to the value of that field, and may not update it to the value of that field if it is the same.

[0414] For example, let us assume that the most recently received NPCA primary channel value is 36, the NPCA transition delay value is 3, and the NPCA transition return delay value is 4. Subsequently, if the STA receives a frame containing the Updated Parameters for NPCA field in which the NPCA primary channel value is 40, the NPCA transition delay value is 3, and the NPCA transition return delay value is 4, the STA may consider that only an update to the NPCA primary channel has occurred and update the NPCA primary channel value (to 36).

[0415] 2) When each field is defined based on Type-Length values

[0416] As shown in Table 5 below, for each NPCA parameter, a Type / ID can be defined and the length of the corresponding field can be defined.

[0417] Type (or ID) Value (e.g., 4 bits) Meaning Field Length (bits) 0 NPCA Enabled 1 NPCA primary channel 8 2 NPCA Switching Delay 8 3 NPCA Switching Back delay 8 4 NPCA minimum duration threshold 8 5 NPCA disabled subchannel bitmap 8 6 NPCA Mode 2 7 Effective Time 7 8 - 15 Reserved -

[0418] Additionally or alternatively, the Updated Parameters for NPCA field may not include all NPCA parameters, but may include only the updated NPCA parameters. Fig. 32 shows an example of the Updated Parameters for NPCA field format based on the Type field.

[0419] Referring to FIG. 32, the Updated Parameters for NPCA field may include only the updated NPCA parameters among the NPCA parameters. For example, if only the NPCA Enabled information and NPCA primary channel information are updated, the Updated Parameters for NPCA field may include i) a Type field set to a value of 0 related to NPCA Enabled (see Table 5) and an NPCA Enabled field indicating the updated value, and ii) a Type field set to a value of 1 related to NPCA primary channel (see Table 5) and an NPCA primary channel field indicating the updated value.

[0420] The above-described Updated Parameters information may be included in a Beacon, Probe Response frame, or Action frame only when the parameter is updated (or when a significant update occurs for the parameter). That is, while the update is complete and the value of the parameter is maintained, the Updated Parameters information may not be included in a Beacon, Probe Response frame, or Action frame.

[0421] The instructions and requirements for the aforementioned CUF, BPCC, and Updated Parameters information can be applied in the same way to (Re)Association Response frames.

[0422] FIGS. 33a and 33b illustrate a first example of a UHR critical update. In FIG. 33, CU represents a critical update, and B may represent a beacon.

[0423] Referring to FIGS. 33a and 33b, a UHR important update (e.g., Updated Parameters for NPCA) is exemplified when AP 1 and AP 2 belong to the same AP MLD. That is, AP 1 and AP 2 are associated with the same AP MLD. Among the (sub)fields of AP 2, the BPCC field and / or the All Updates Included field may be fields corresponding to AP 1. The BPCC, CUF, UCUF, and / or All Updates Included fields may be indicated based on at least one of the methods described above.

[0424] It can be identified that an update to the EDCA parameter set has occurred in B11 of AP1, and AP2 can accordingly increase BPCC from 3 to 4 in B21 and set CUF to 1. Since the EDCA parameter set is not a new UHR feature / mode, UCUF remains at 0, and since the EDCA parameter set is not included in the Per-STA Profile subelement even if it is updated, All Updates Included can be set to 0.

[0425] It can be identified that an update for Updated Parameters For NPCA corresponding to UHR feature / mode = NPCA has occurred in B12 of AP 1, and accordingly, AP 2 can increase BPCC from 4 to 5 and set UCUF to 1 in B22. In addition, since the Updated Parameters For NPCA is included in the Per-STA Profile subelement corresponding to AP 1, All Updates Included can be set to 1. Additionally, CUF can be maintained at 1 until the next DTIM, B24.

[0426] After that, unless a significant update occurs, the values ​​set up to B22 can be maintained until the next DTIM Beacon, B24.

[0427] Non-AP STAs connected to AP1 can identify that an important update has occurred based on the UCUF provided by AP2, even if they are in a doze state for power saving operations. For example, as shown in FIG. 33, AP2, the reporting AP, can include important update information generated by AP1, the reported AP, in a beacon and transmit it. At this time, the effective time can be used to indicate from what point in time the Updated Parameters for NPCA are applied. In FIG. 33, the effective time is set to 0000 0101 (i.e., after 5 TBTT).

[0428] Case 1) For example, the Updated Parameters information for the NPCA may be included and transmitted in the frame (e.g., beacon frame / probe response frame / (re)connection response frame / link reset response frame) only up to T = Next DTIM Beacon. In this case, since the Updated Parameters information for the NPCA is not included from B25 onwards, UCUF is set to 0 and the All Updated Included field can be set to 0. This resolves the Beacon Bloating issue, where overhead problems occur due to the inclusion of a large amount of information in the beacon.

[0429] Case 2) For example, the Updated Parameters information for NPCA may be included in a frame (e.g., beacon frame / probe response frame / (re)connection response frame / link reset response frame) and transmitted until T (T depending on parameter) which depends on the parameter (e.g., until the validity period). For example, as shown in FIG. 33, the Updated Parameters for NPCA may be applied after 5TBTT (from B26). In this case, since the Updated Parameters information for NPCA is not only included in the frame and transmitted until Next DTIM, UCUF may be set to 1 and the All Updates Included field to 1 in B25 after Next DTIM. Additionally, based on the validity period, UCUF may be reset to 0 and the All Updates Included field to 0 starting from B26.

[0430] FIGS. 34a and 34b show a second example of a UHR critical update. In FIG. 34, CU represents a critical update, and B may represent a beacon.

[0431] Referring to FIGS. 34a and 34b, the NPCA Mode field and the NPCA Minimum Duration Threshold field may be included in a frame (e.g., beacon frame / probe response frame / (re)connection response frame / link reset response frame) and transmitted as critical update parameters. For example, after announcing NPCA Mode = 0 and NPCA Minimum Duration Threshold = 3, a critical update may occur to NPCA Mode = 1 and NPCA Minimum Duration Threshold = 4. When the NPCA Mode is updated to 1, this may indicate a change in the NPCA mode from PPDU-based NPCA to TXOP-based NPCA. In the NPCA mode of TXOP-based NPCA, the duration for performing the NPCA may be set based on the TXOP of the OBSS traffic. At this time, when the NPCA minimum duration threshold is 4 (i.e., NPCA minimum duration threshold = 256us), the STA compares the TXOP of the OBSS traffic with 256us, and based on the comparison, if the TXOP of the OBSS traffic is greater than 256us, the STA can switch to the NPCA primary channel (considering the STA's NPCA Switching Delay) and perform NPCA.

[0432] Additionally or alternatively, if the NPCA Minimum Duration Threshold is defined according to the NPCA Mode (e.g., if PPDU_NPCA Minimum Duration Threshold and TXOP_NPCA Minimum Duration Threshold are defined), the NPCA Mode and the NPCA Minimum Duration Threshold associated with that NPCA Mode may be included in the frame and transmitted together. For example, if the NPCA Mode is updated from 0 to 1, the TXOP_NPCA Minimum Duration Threshold may also be included in the frame and transmitted.

[0433] Additionally or alternatively, if a single NPCA Minimum Duration Threshold is used, that NPCA Minimum Duration Threshold may be used when the NPCA Mode is updated, regardless of the NPCA Mode.

[0434] According to various embodiments of the present disclosure, the event list (or element list) of important updates may include the insertion of UHR Parameters Update elements. In other words, the insertion of UHR Parameters Update elements (regarding BSS parameters of AP) may be classified as an important update.

[0435] The following actions scheduled to be performed by the AP require an Advance Notification Procedure (or, a procedure for notifying a UHR Parameters Update element (e.g., Parameters Update field / element)):

[0436] - If the AP is a mobile AP and you intend to enable, disable, or update one or more parameters for DPS operation on the mobile AP, or

[0437] - When enabling, disabling, or updating one or more parameters for NPCA (Non-Primary Channel Access), or

[0438] - When enabling, disabling, or updating one or more parameters for the DBE, or

[0439] - When updating the MaxStandaloneDUOBSRP parameter for DUO (Dynamic Unavailability Operation),

[0440] - When enabling, disabling, or updating one or more parameters for P-EDCA (Prioritized Enhanced Distributed Channel Access), or

[0441] - When enabling, disabling, or updating one or more parameters for AP PUO (Periodic Unavailability Operation) mode, or

[0442] - When enabling or disabling reception of UHR (Ultra-High Reliability) ELR (Enhanced Long Range) PPDU.

[0443] The operation takes effect on the AP at the TBTT indicated by the Countdown Timer field within the UHR Parameters Update element.

[0444] After an action for activating a UHR mode or updating parameters takes effect, the AP must use an enhanced notification procedure to continue operations in the UHR mode based on the specified parameters until a subsequent change to the UHR mode takes effect.

[0445] A UHR AP associated with an AP MLD must initiate an advanced notification procedure when there is an update to the defined UHR operation mode for one of the following two cases:

[0446] If the update is related to the AP MLD to which the AP is linked, or any AP linked to the same AP MLD as the AP.

[0447] If the AP corresponds to a Transmitted BSSID within a Multiple BSSID set, and the update relates to the following: i) an AP MLD associated with any Nontransmitted BSSID within that set, or ii) any AP associated with an AP MLD identical to one of the Nontransmitted BSSIDs within that set.

[0448] In a TBTT where an AP associated with an AP MLD initiates an enhanced notification procedure for the cases described above, the AP must perform the following in the Beacon frame it transmits.

[0449] - Set the Enhanced Critical Update Flag (e.g., UCUF, UHR CUF) in the Capability Information field to 1.

[0450] - Include the Critical Updates Indicator field within the Partial Virtual Bitmap field of the TIM element and perform the following:

[0451] Sends a value of 1 to the Critical Update Type field of the Critical Updates Indicator field.

[0452] Increases the value in the Critical Update Counter field of the Critical Updates Indicator field by 1 (modulo 16).

[0453] - Increase the value of the Enhanced BSS Parameter Change Count (e.g., UHR BPCC) field corresponding to each affected AP by 1 (modulo 16), send a value of 1 to the Critical Update Type field corresponding to each affected AP, and set the Enhanced All Updates Included field to 1.

[0454] If the affected AP is a Colocated UHR AP, the Enhanced BSS Parameter Change Count, Critical Update Type, and Enhanced All Updates Included fields are transmitted in the Enhanced Critical Updates Information field present in the TBTT Information field of the Reduced Neighbor Report (RNR) element.

[0455] If the affected AP is a transmitting AP or an AP corresponding to a Nontransmitted BSSID within the same Multiple BSSID set as the transmitting AP, the Enhanced BSS Parameter Change Count, Critical Update Type, and Enhanced All Updates Included fields are transmitted in the Enhanced Critical Updates Information field included in the Common Info field of the Basic Multi-Link element.

[0456] The Enhanced BSS Parameter Change Count field is transmitted in the Enhanced Critical Updates Information field within the STA Info field of the Basic Multi-Link element carried in the (Re)Association Response or Link Reconfiguration Response frame.

[0457] - Include the UHR Parameters Update element (e.g., Parameters Update field / element) in the beacon frame.

[0458] Figure 35 shows an example of a Capability Information field format including an Enhanced Critical Update Flag field.

[0459] Referring to FIG. 35, the Capability Information field may include the Enhanced Critical Update Flag field. The Enhanced Critical Update Flag field is set to 1 in beacon and probe response frames transmitted by the UHR AP when the AP intends to update one or more parameters for the UHR mode in Table 6 below (or when an event included in the critical update event list occurs). Otherwise, the field is set to 0. In frames transmitted by non-AP STAs, this field is reserved.

[0460] Figure 36 shows an example of an Enhanced Critical Updates Information field format including an Enhanced BSS Parameter Change Count field.

[0461] Referring to FIG. 36, the Enhanced Critical Updates Information field may include the Enhanced BSS Parameter Change Count field (4 bits, B0 to B3). The Enhanced BSS Parameter Change Count field may indicate an unsigned integer that is initialized to 0. This value is initialized to 0 when the BSS starts. The field is incremented by 1 when the AP intends to update one or more parameters for the UHR mode in Table 6 below for the reported AP (or when an event included in the critical update event list occurs) (modulo 16).

[0462] Figure 37 shows an example of a TBTT Information field format including an Enhanced Critical Updates Information field.

[0463] Referring to FIG. 37, the TBTT Information field may include the Enhanced Critical Updates Information field. The Enhanced Critical Updates Information field may exist when the reporting target AP is a colocated UHR AP (i.e., when the Colocated AP field is set to 1). Otherwise, the Enhanced Critical Updates Information field may not exist.

[0464] Figure 38 shows an example of the Presence Bitmap subfield format of Basic ML IE.

[0465] Referring to Fig. 38, the Presence Bitmap subfield of Basic ML IE may include an Enhanced Critical Updates Information Present field (e.g., UHR BSS Parameters Change Count Present field). The Enhanced Critical Updates Information Present subfield may be set to 1 if the Enhanced Critical Updates Information subfield (e.g., UHR BPCC field) is included in the Common Info field of Basic ML IE. Otherwise, the Enhanced Critical Updates Information Present subfield is set to 0.

[0466] A non-AP STA sets the Enhanced Critical Updates Information Present subfield to 0 in the Basic ML IE it transmits. In the Basic ML IE transmitted by the AP, the Enhanced Critical Updates Information Present subfield is set to 1. However, this exception does not apply if the Basic ML IE is transmitted included in an Authentication frame or a Fast BSS Transition (FT) action frame.

[0467] Figure 39 shows an example of the STA Control field format of Basic ML IE.

[0468] Referring to Fig. 39, the STA Control field of Basic ML IE may include an Enhanced Critical Updates Information Present subfield (e.g., UHR BSS Parameters Change Count Present field). The Enhanced Critical Updates Information Present subfield may be set to 1 if the STA Info field of Basic ML IE includes an Enhanced Critical Updates Information subfield (e.g., UHR BPCC field). Otherwise, the Enhanced Critical Updates Information Present subfield is set to 0.

[0469] A non-AP STA sets the Enhanced Critical Updates Information Present subfield to 0 in the Basic ML IE it transmits. An AP sets the Enhanced Critical Updates Information Present subfield to 1 in the Basic ML IE included in the (Re)Association Response or Link Reconfiguration Response frame, and to 0 in other frames.

[0470] Figure 40 shows an example of the UHR Parameters Update element format.

[0471] Referring to FIG. 40, the UHR Parameters Update element (e.g., Parameters Update field / element) may include a Countdown Timer field and a Mode Tuple List field.

[0472] The Countdown Timer field is set to the number of remaining TBTTs until the time when the update(s) specified in the UHR Parameter Update element are applied in the AP corresponding to the UHR Parameter Update element. If the Countdown Timer field value is 1, it indicates that the update(s) will be applied at the next TBTT. If the Countdown Timer field value is greater than 127, it indicates that the update(s) specified in the UHR Parameter Update element have already been applied. If the Countdown Timer field is set to a value greater than 127, the corresponding update(s) have already been applied at the previous TBTT by (Countdown Timer field value - 127).

[0473] The Mode Tuple List field contains one or more Mode Tuple fields.

[0474] Figure 41 shows an example of a Mode Tuple field format.

[0475] Referring to FIG. 41, the Mode Tuple field may include a Mode ID field (e.g., the Updated Parameters Presence Bitmap field) and a Mode Specific Parameters field (e.g., the Updated Parameters field). The Mode ID field contains an identifier for the UHR mode associated with the corresponding mode tuple. The encoding of the Mode ID field is defined in Table 6:

[0476] Value Mode 0DPS1NPCA2DUO3P-EDCA4DBE5AP PUO6ELR Reception 7-63 Reserved

[0477] The definition of the Mode Specific Parameters field depends on the value of the Mode ID field of the corresponding mode tuple. For example, if the Mode ID field is set to a value related to DPS (i.e., 0), the Mode Specific Parameters field may contain the Mode Specific Parameters field for DPS (or the Updated Parameters field for DPS).

[0478] For example, if the Mode ID field is set to a value associated with NPCA (i.e., 1), the Mode Specific Parameters field may include the Mode Specific Parameters field for NPCA (or the Updated Parameters field for NPCA). More specifically, when the Mode ID field value is 1:

[0479] - The Mode Tuple field corresponds to NPCA;

[0480] - The Mode Specific Parameters field contains parameters for NPCA.

[0481] The Mode Specific Parameters field for NPCA is defined in Fig. 41.

[0482] Figure 42 shows an example of the Mode Specific Parameters field format for NPCA.

[0483] Referring to FIG. 42, the Mode Specific Parameters field for NPCA may include at least one of the NPCA Primary Channel field, NPCA Minimum Duration Threshold field, NPCA Switch Delay field, NPCA Switch Back Delay field, Initial NPCA QSRC field, MOPLEN NPCA field, NPCA Disabled Subchannel Bitmap Present field, reserved field, or NPCA Disabled Subchannel Bitmap field. The field encoding of the Mode Specific Parameters field for NPCA may be the same as the encoding of the corresponding fields within the NPCA Operation Parameters field.

[0484] The NPCA Primary Channel field indicates the channel number of the channel within the BSS bandwidth that the NPCA AP and the connected NPCA non-AP STA will switch to in order to perform NPCA operation.

[0485] The NPCA Minimum Duration Threshold field indicates the minimum duration of inter-BSS activity that must be directed from the Primary channel of the BSS as a prerequisite for the NPCA AP and the connected NPCA non-AP STA to switch to the NPCA Primary channel for NPCA operation. The NPCA Minimum Duration Threshold field is set as defined in Table 7.

[0486] NPCA Minimum Duration Threshold (NMDT) Field Description0-15The NPCA minimum duration threshold T, in units of 128 μs, is T = 512 + NMDT × 128, where NMDT is the field value, which yields a minimum of 512 μs and a maximum of 2432 μs.The minimum is chosen to cover at least the transmission time of NPCA ICF and ICR exchange plus a typical Data and Ack / BA exchange using non-HT or non-HT duplicate PPDU format with 6 Mb / s data rate.

[0487] The NPCA Switch Delay field indicates the time required for the NPCA AP to switch from the BSS Primary channel to the NPCA Primary channel in units of 4μs. The NPCA Switch Back Delay field indicates the time required for the NPCA AP to return from the NPCA Primary channel to the BSS Primary channel in units of 4μs.

[0488] The Initial NPCA QSRC field represents the value used to initialize the EDCAF QSRC[AC] variable when the NPCA STA in the BSS switches to NPCA operation.

[0489] The MOPLEN NPCA field indicates which conditions can be used to initiate an NPCA operation. If this field value is 1, it indicates that both PHYLEN NPCA and MOPLEN NPCA operations are allowed within the BSS. If this field value is 0, it indicates that only PHYLEN NPCA operations are allowed within the BSS.

[0490] The NPCA Disabled Subchannel Bitmap Present field indicates whether the NPCA disabled subchannel bitmap field exists. If this field is 1, it indicates that the NPCA disabled subchannel bitmap field exists.

[0491] The NPCA Disabled Subchannel Bitmap field is in bitmap format, and the lowest numbered bit corresponds to the lowest frequency subchannel among all 20 MHz subchannels within the BSS bandwidth. Each subsequent bit of the bitmap corresponds to a 20 MHz subchannel with a frequency one step higher. If a bit of the bitmap corresponding to the BSS bandwidth is set to 1, it indicates that the corresponding 20 MHz subchannel has been punctured; if set to 0, it indicates that it has not been punctured. Bits of the bitmap outside the BSS bandwidth are reserved. This field exists only when the value of the NPCA Disabled Subchannel Bitmap Field Existence field is 1; otherwise, it does not exist.

[0492] The reporting AP must begin including the UHR Parameters Update element in the Beacon, Probe Response, Link Reconfiguration Response, and / or (Re)Association Response frames it transmits prior to the dot11UHRParamUpdateAdvNotificationInterval period from the time when the action requiring enhanced notification is scheduled to occur. It must also include the element until it includes the DTIM beacon immediately after the TBTT in which the action occurs. The Parameter Update Adv Notification Interval may indicate, in TBTT counts, how early the AP should initiate the enhanced notification procedure for an upcoming critical update.

[0493] After the DTIM beacon immediately following the TBTT where the operation occurs, the reporting AP may include the UHR Parameters Update element in its beacon and probe response frames for an additional dot11UHRParamUpdatePostNotificationInterval beacon cycle, and must not include the UHR Parameters Update element thereafter until the next enhanced notification procedure begins.

[0494] On the link where the affected AP is operating, the UHR Parameters Update element carrying update information for the AP must be included outside of any Multiple BSSID element and Basic Multi-Link element.

[0495] In other link(s) of the AP MLD to which the affected AP is connected, the UHR Parameters Update element carrying update information for the AP must be transmitted within the Basic Multi-Link element in the per-STA profile corresponding to the affected AP.

[0496] In the present disclosure, the first STA may transmit a frame / PPDU containing at least one of first information, second information, or third information to one or more other STAs when a significant update occurs for the first STA or when a significant update occurs for a second STA belonging to the same MLD as the first STA.

[0497] For example, a frame can be a Beacon, Probe Response, (Re)Association Response frame, or Action frame.

[0498] For example, the first information may include a CUF. The CUF may be a UCUF considering the next generation. The value of the CUF may be set to 1 if a significant update to the UHR feature / mode occurs. The UCUF may be indicated based on the Capability Information field and / or the reserve field of the Extended Capabilities element. The CUF may be added for each generation.

[0499] For example, the second information may include a BPCC. The BPCC for the first STA may be included in the Per-STA Profile subelement corresponding to the first STA in the Common Info field or Link Info field of the Basic ML IE, either per generation or collectively. The BPCC for the second STA may be included in the TBTT Information field corresponding to the second STA in the RNR IE, either per generation or collectively.

[0500] For example, third information may include an Updated Parameters field. The Updated Parameters field for the first STA may be included in the Per-STA Profile subelement corresponding to the first STA in the Common Info field or the Link Info field. The Updated Parameters field for the second STA may be included in the Per-STA Profile subelement corresponding to the second STA in the Link Info field. Additionally or alternatively, when the Updated Parameters field is included, the All Updates Included field of the RNR IE corresponding to the second STA may be reused and set to 1, or UHR All Updates Included may be additionally included and set to 1.

[0501] Additionally or alternatively, the Updated Parameters field may be included up to the point in time based on the next DTIM Beacon or Updated Parameters information of the first STA.

[0502] Additionally, Updated Parameters information may be included in the frame only when it is updated based on the occurrence of an event included in the important update event list. That is, Updated Parameters information may not be included in the frame while the update is complete and the value of the parameter is maintained.

[0503] In the present disclosure, an STA receiving important update information (e.g., UCUF, UHR CUF, UHR BPCC, and / or Parameters update field / element) from an STA can perform frame detection and obtain important update information and / or information of parameters associated with the important update through frame detection.

[0504] 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.

[0505] For example, the processor (121) and / or processing chip (124) of FIG. 1 may be configured to perform operations performed in the AP in the present disclosure by executing instructions stored in memory (122). The operations include: setting at least one of a critical update flag or a BSS parameter change count field to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA); and transmitting a frame including at least one of the critical update flag or the BSS parameter change count field, wherein the frame includes a parameter update element, and the parameter update element includes one or more parameters for the NPCA.

[0506] For example, the processor (111), processing chip (114) of FIG. 1 and / or the processor (510) of FIG. 5 may be configured to perform operations performed in the STA in the present disclosure by executing instructions stored in memory (112, 520). The operations include: receiving a frame containing at least one of a critical update flag or a basic service set (BSS) parameter change count field; and obtaining a parameter update element in the frame based on at least one of the critical update flag or the BSS parameter change count field, wherein at least one of the critical update flag or the BSS parameter change count field is set to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA), and the parameter update element includes one or more parameters for the NPCA.

[0507] 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.

[0508] 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 in the 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: setting at least one of a critical update flag or a BSS parameter change count field to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA); and transmitting a frame including at least one of the critical update flag or the BSS parameter change count field, wherein the frame includes a parameter update element, and the parameter update element includes one or more parameters for the NPCA.

[0509] 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 in the STA 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: receiving a frame containing at least one of a critical update flag or a basic service set (BSS) parameter change count field; The method includes an operation to obtain a parameter update element in the frame based on at least one of the important update flag or the BSS parameter change count field, wherein at least one of the important update flag or the BSS parameter change count field is set to a corresponding value based on the existence of an update of one or more parameters for non-primary channel access (NPCA), and the parameter update element includes one or more parameters for the NPCA.

[0510] 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).

[0511] 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.

[0512] 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.

[0513] 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.

[0514] 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.

[0515] 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.

[0516] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0517] 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.

[0518] 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.

[0519] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0520] 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.

[0521] 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.

[0522] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0523] 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.

[0524] 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.

[0525] 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.

[0526] The present disclosure may have various advantageous effects.

[0527] For example, by transmitting parameters related to NPCA as critical updates only when an update (e.g., addition / modification / change) of the parameter occurs, overhead can be reduced compared to a method in which parameters related to NPCA are transmitted via beacons, probe response frames, etc., every cycle (i.e., different from critical updates).

[0528] 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.

[0529] 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 an access point (AP) sets at least one of a critical update flag or a BSS parameter change count field to a corresponding value based on the existence of updates to one or more parameters for non-primary channel access (NPCA); and The above AP includes the step of transmitting a frame comprising at least one of the above important update flag or the above BSS parameter change count field, and The above frame includes a parameter update element, and A method in which the above parameter update element includes one or more parameters for the above NPCA.

2. The method of claim 1, wherein one or more parameters for the NPCA include at least one of information regarding the NPCA primary channel, information regarding the NPCA switching delay, information regarding the NPCA switching back delay, information regarding the NPCA minimum duration threshold, information regarding the NPCA disabled subchannel bitmap, information regarding whether the NPCA operation is enabled, information regarding the TB (trigger-based) mode, information regarding the NPCA mode, or information regarding the effective time.

3. A method according to claim 2, wherein the effective time includes the time during which one or more parameters for the NPCA are applied after the frame is transmitted.

4. In claim 2, one or more parameters for the NPCA are applied after the frame is transmitted and after one or more TBTTs (target beacon transmission times), and Information regarding the above validity time is a method of indicating the number of the above one or more TBTTs.

5. The method of claim 2, wherein the effective time is indicated based on a time synchronization function (TSF) or a partial TSF.

6. In claim 1, the parameter update element further comprises one or more other parameters for the NPCA for which the update does not exist, and One or more parameters for the NPCA having the above update are set to an updated value relative to the previous value, and A method in which one or more other parameters for the NPCA for which the above update does not exist are set to the same value as the previous value.

7. In claim 1, one or more other parameters for the NPCA for which the update does not exist are excluded from the parameter update element, and A method in which the above parameter update element further includes, for each of one or more parameters for the NPCA in which the update exists: type information; an ID (identifier) ​​value; or information regarding the length of the corresponding field.

8. In claim 1, based on the existence of an update of one or more parameters for the NPCA: The above important update flag is set to 1; and A method to increase the value of the above BSS parameter change count field by 1.

9. The method of claim 1, wherein the important update flag is included in the capability information field of the frame.

10. The method of claim 1, wherein the BSS parameter change count field is included in the TBTT (target beacon transmission time) information field in the reduced neighbor report element of the frame.

11. The method of claim 1, wherein the BSS parameter change count field is included in a common information field in a basic multi-link element of the frame.

12. A method according to claim 11, wherein the presence bitmap field of the basic multi-link element includes information regarding whether the BSS parameter change count field exists in the common information field of the basic multi-link element.

13. The method of claim 1, wherein the BSS parameter change count field is included in the STA (station) information field in the basic multi-link element of the frame.

14. A method according to claim 13, wherein the STA control field in the basic multi-link element includes information regarding whether the BSS parameter change count field exists in the STA information field of the basic multi-link element.

15. In claim 1, the parameter update element includes a field related to a mode, and A method in which, based on the fact that the value of a field related to the above mode is a value related to the above NPCA, the parameter update element includes one or more parameters for the above NPCA.

16. The method of claim 1, wherein the parameter update element is included in a per-STA profile corresponding to the affected AP associated with the update in a basic multi-link element.

17. The method of claim 1, wherein the parameter update element includes a DTIM (delivery traffic indication map) beacon after the time at which the update occurred.

18. The method of claim 1, wherein the frame is a beacon frame, a probe response frame, a connection response frame, a reconnection response frame, or a link reset response frame.

19. Regarding 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: An operation to set at least one of the critical update flag or BSS parameter change count fields to a corresponding value based on the existence of updates to one or more parameters for NPCA (non-primary channel access); and The operation includes transmitting a frame comprising at least one of the above important update flag or the above BSS parameter change count field, and The above frame includes a parameter update element, and The above parameter update element is an AP including one or more parameters for the above NPCA.

20. 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: An operation to set at least one of the critical update flag or BSS parameter change count fields to a corresponding value based on the existence of updates to one or more parameters for NPCA (non-primary channel access); and The operation includes transmitting a frame comprising at least one of the above important update flag or the above BSS parameter change count field, and The above frame includes a parameter update element, and The above parameter update element is a device comprising one or more parameters for the above NPCA.

21. 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: An operation to set at least one of the critical update flag or BSS parameter change count fields to a corresponding value based on the existence of updates to one or more parameters for NPCA (non-primary channel access); and The operation includes transmitting a frame comprising at least one of the above important update flag or the above BSS parameter change count field, and The above frame includes a parameter update element, and The above parameter update element is a CRM that includes one or more parameters for the above NPCA.

22. A step in which a STA (station) receives a frame containing at least one of a critical update flag or a basic service set (BSS) parameter change count field; and The above STA includes the step of obtaining a parameter update element in the frame based on at least one of the important update flag or the BSS parameter change count field, and At least one of the above important update flag or the above BSS parameter change count field is set to a corresponding value based on the existence of updates to one or more parameters for NPCA (non-primary channel access), and A method in which the above parameter update element includes one or more parameters for the above NPCA.

23. Regarding STA(station), 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 operation of receiving a frame including at least one of a critical update flag or a basic service set (BSS) parameter change count field; and The method includes an operation to obtain a parameter update element from the frame based on at least one of the above important update flag or the above BSS parameter change count field, and At least one of the above important update flag or the above BSS parameter change count field is set to a corresponding value based on the existence of updates to one or more parameters for NPCA (non-primary channel access), and The above parameter update element is a STA containing one or more parameters for the above NPCA.

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