Scheduling for frame exchange in high frequency band in wireless LAN system

Abstract

The present disclosure relates to scheduling for frame exchange in a high frequency band. According to an embodiment of the present disclosure, a method performed by an access point (AP) multi-link device (MLD) comprises the steps in which: a first AP affiliated with the AP MLD and related to a first frequency band transmits information on one or more other APs affiliated with the AP MLD and related to a second frequency band higher than the first frequency band; the first AP receives one or more request frames for requesting an association between a second AP among the one or more other APs and one or more stations (STAs), wherein each of the one or more STAs is affiliated with a corresponding non-AP MLD and is related to the second frequency band; the first AP transmits one or more response frames to the one or more request frames; and the first AP transmits scheduling information of the second AP, wherein the scheduling information includes at least one of i) identification information of an initiator initiating frame exchange among STAs related to the second AP, ii) identification information of at least one responder performing the frame exchange with the initiator among the STAs related to the second AP, and iii) information on a time period for the frame exchange, and the STAs related to the second AP include the second AP and the one or more STAs associated with the second AP.

Description

Scheduling for frame switching in the high-frequency band in wireless LAN systems

[0001] The present disclosure relates to scheduling for frame switching in a high-frequency band.

[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] For example, recent wireless LAN technology is evolving in a direction that utilizes various frequency bands to provide high data transfer rates and low latency. In particular, wireless LAN standards represented by IEEE 802.11ad and IEEE 802.11ay have introduced technology that provides ultra-high-speed transfer rates of gigabit or higher by using millimeter wave (mmWave) bands such as the approximately 60 GHz band.

[0004] While the mmWave band offers the advantage of supporting very high transmission rates due to its wide bandwidth, its short wavelength and strong directional properties result in significant path loss and vulnerability to blocking effects caused by walls or human bodies. Consequently, mmWave-based Wi-Fi systems require additional procedures to maintain communication quality, such as beamforming, beam training, and beam tracking between transmitting and receiving terminals.

[0005] In addition, since link stability can easily degrade in mmWave environments due to terminal mobility, reflection and shielding by surrounding objects, and human rotation, standards aim to prevent link disconnection through techniques such as beam switching, link monitoring, and candidate beam maintenance. In IEEE 802.11ay, support for more spatial streams compared to 802.11ad, improved beam management techniques, and MU-MIMO-based transmission are being discussed.

[0006] As such, while mmWave-based Wi-Fi enables ultra-high-speed wireless communication, it faces challenges such as difficulty in securing stable links due to radio wave characteristics and increased overhead caused by beam management procedures. Therefore, there is a continuous demand for technologies to enhance link stability, improve beam management efficiency, and reduce transmission delay in the mmWave band.

[0007] The present disclosure provides a method and apparatus for scheduling frame switching in a high-frequency band in a wireless LAN system.

[0008] According to an embodiment of the present disclosure, a method performed by an access point (AP) multi-link device (MLD) comprises: a first AP associated with the AP MLD and associated with a first frequency band transmitting information about one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; the first AP receiving one or more request frames to request an association between the second AP and one or more stations (STAs) among the one or more other APs, wherein each of the one or more STAs is associated with a corresponding non-AP MLD and associated with the second frequency band; and the first AP transmitting one or more response frames for the one or more request frames. The method includes the step of the first AP transmitting scheduling information to the second AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and the one or more STAs connected to the second AP.

[0009] According to an embodiment of the present disclosure, a method performed by a non-AP (access point) MLD (multi-link device) comprises: a first STA (station) associated with the non-AP MLD and associated with a first frequency band receiving information from a first AP associated with the AP MLD and associated with the first frequency band regarding one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; the first STA transmitting a request frame to request a connection between a second AP among the one or more other APs and a second STA associated with the non-AP MLD and associated with the second frequency band; and the first STA receiving a response frame for the request frame. The method includes the step of the first STA receiving scheduling information for the second AP from the first AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and one or more STAs connected to the second AP.

[0010] In various embodiments, devices for implementing the methods described above are provided.

[0011] The present disclosure may have various advantageous effects.

[0012] For example, an STA connected to an MLD and operating in the sub-7GHz band can be scheduled to perform frame switching with an STA connected to the same MLD and operating in the mmWave band. By performing such schedule-based frame switching, unnecessary power consumption can be reduced.

[0013] 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.

[0014] FIG. 1 shows an example of a transmitting device and / or receiving device of the present disclosure.

[0015] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0016] Figure 3 is a diagram illustrating a general link setup process.

[0017] Figure 4 illustrates an example of a multi-link (ML).

[0018] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0019] 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.

[0020] Figure 7 shows the operation according to UL-MU.

[0021] Figure 8 shows an example of a MAC frame header.

[0022] Figure 9 shows an example of a beamforming training procedure.

[0023] Figure 10 shows an example of an initiator TXSS and / or an initiator RXSS.

[0024] Figure 11 shows the responder TXSS and / or responder RXSS.

[0025] Figure 12 shows examples of AP MLD and Non-AP MLD that support the mmWave band.

[0026] Figure 13 shows an example of a multi-link discovery and multi-link setup procedure.

[0027] FIG. 14 illustrates an example of a method performed on an AP MLD in a scheduling procedure for frame switching in a high-frequency band according to an embodiment of the present disclosure.

[0028] FIG. 15 illustrates an example of a method performed by a non-AP MLD in a scheduling procedure for frame switching in a high-frequency band according to an embodiment of the present disclosure.

[0029] Figure 16 shows an example of scheduling based on AID allocation.

[0030] Figure 17 shows an example of scheduling based on a trigger field.

[0031] Figure 18 shows an example of scheduling based on Broadcast AID.

[0032] Figure 19 shows an example of scheduling based on a Broadcast field.

[0033] Figure 20 shows an example of scheduling based on the trigger field / broadcast field.

[0034] Figure 21 shows an example of scheduling when the Source AID / Destination AID is a Broadcast AID.

[0035] Figure 22 shows an example of an announcement for BF.

[0036] Figure 23 shows an example of SLS time information.

[0037] Figure 24 shows an example of a case where BFTP is indicated based on the time gap.

[0038] Figure 25 shows an example of a field / element containing scheduling information.

[0039] Figure 26 shows an example of I-TXSS in the SLS Phase.

[0040] Figure 27 shows examples of I-TXSS and R-TXSS in the SLS Phase.

[0041] Figure 28 shows an example of I-RXSS in the SLS Phase.

[0042] Figure 29 shows an example of I-TXSS & R-RXSS in the SLS Phase.

[0043] 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.”

[0044] 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.”

[0045] 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.”

[0046] 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.”

[0047] 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.”

[0048] 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.”

[0049] Technical features described individually within one drawing in this disclosure may be implemented individually or simultaneously.

[0050] 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.

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

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

[0053] An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of 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.

[0054] For example, the STA (110, 120) can perform the role of an access point (AP) or a non-AP. That is, the STA (110, 120) of 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.

[0055] 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.

[0056] 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.

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

[0058] The first STA (110) may include a processor (111), memory (112), and a transceiver (113). The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two blocks / functions may be implemented through a single chip.

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

[0060] For example, the first STA (110) can perform the intended operation of the AP. For example, the processor (111) of the AP can receive a signal through the transceiver (113), process the received signal, generate a transmitted signal, and perform control for transmitting the signal. The memory (112) of the AP can store the signal received through the transceiver (113) (i.e., the received signal) and the signal to be transmitted through the transceiver (i.e., the transmitted signal).

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

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

[0063] For example, the operation of the device 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).

[0064] 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).

[0065] 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.

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

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

[0068] The mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, User STA, network, Base Station, Node-B, AP (Access Point), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and / or transmitting Apparatus described below may refer to the STA (110, 120) shown in side drawings (a) / (b) of FIG. 1, or the processing chip (114, 124) shown in side drawing (b) of FIG. 1. That is, the technical features of the present 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).

[0069] For example, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal being received by the 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.

[0070] Referring to side view (b) of FIG. 1, software code (115, 125) may be included in memory (112, 122). The software code (115, 125) may include instructions that control the operation of the processor (111, 121). The software code (115, 125) may be included in various programming languages.

[0071] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The processor may be an application processor (AP). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an 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.

[0072] 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.

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

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

[0075] 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).

[0076] 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.

[0077] 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).

[0078] 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).

[0079] 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).

[0080] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0081] 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.

[0082] Figure 3 is a diagram illustrating a general link setup process.

[0083] 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.

[0084] 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).

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] The following describes multi-link (ML).

[0092] Terms related to multiple links can be defined as follows:

[0093] - 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;

[0094] - Multi-link operation (MLO) can refer to operations such as discovery, authentication, multi-link establishment, and frame switching between two MLDs;

[0095] - 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;

[0096] - An AP MLD is an MLD where each STA associated with it is an AP;

[0097] - A non-AP MLD is an MLD in which each STA associated with it is a non-AP STA;

[0098] - The linked AP is the AP STA linked to the AP MLD;

[0099] - The linked non-AP STA is the non-AP STA linked to the non-AP MLD.

[0100] Figure 4 illustrates an example of multiple links.

[0101] 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).

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] Below, more specific features regarding the ML setup are explained.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] FIG. 5 shows a modified example of a transmitting device and / or receiving device of the present disclosure.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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).

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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).

[0122] 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.

[0123] 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.

[0124] 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).

[0125] 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.

[0126] 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}.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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".

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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).

[0143] 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).

[0144] 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.

[0145] 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.

[0146] 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).

[0147] 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.

[0148] 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.

[0149] 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).

[0150] 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).

[0151] The structure and types / subtypes of MAC frames are described below.

[0152] 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.

[0153] 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).

[0154] 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.

[0155] 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).

[0156] 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).

[0157] 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.

[0158] 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).

[0159] The following describes beamforming (e.g., DMG beamforming).

[0160] Beamforming (BF) is a mechanism used by a pair of STAs to secure the DMG link resources necessary for subsequent communication. BF training is a bidirectional BF frame or Short SSW PPDU transmission sequence using a sector sweep, providing the necessary signaling to enable each STA to determine the antenna system configuration suitable for both transmission and reception. Once BF training is successfully completed, BF can be established. The BF frames are SSW frames, DMG beacon frames, SSW-feedback frames, SSW-Ack frames, or BRP frames.

[0161] Figure 9 shows an example of a beamforming training procedure.

[0162] Short SSW PPDUs are used between EDMG STAs. Unless otherwise specified, the rules applicable to SSW frame transmission of the present disclosure also apply to Short SSW PPDU transmission.

[0163] In the present disclosure, an STA that initiates BF training through the transmission of a BF frame is referred to as the initiator, and a BF frame receiving STA that participates in BF training together with the initiator is referred to as the responder. In the case of BF training occurring within an A-BFT allocation, an AP or PCP is the initiator, and an STA that is neither an AP nor a PCP is the responder. In the case of BF training occurring during an SP allocation, the source DMG STA of the SP is the initiator, and the destination DMG STA of the SP is the responder. In the case of BF training occurring during a CBAP allocation, the TXOP holder is the initiator and the TXOP responder is the responder, and the Duration field value of the transmitted BF frame does not limit the duration of the BF training procedure.

[0164] A link connecting an initiator to a responder is called an initiator link, and a link connecting a responder to an initiator is called a responder link.

[0165] BF training begins with the initiator's SLS. A beam refinement protocol (BRP) may follow if requested by the initiator or responder. The purpose of the SLS phase is to enable communication between the two participating STAs at the DMG control mode rate or a higher MCS. Typically, the SLS phase provides only transmit BF training. The purpose of the BRP phase is to enable receive training and iteratively refine the AWV of both the transmitter and receiver on both participating STAs. If one of the participating STAs chooses to use only one transmit antenna pattern, receive training may be performed as part of the SLS.

[0166] A STA may have one or more DMG antennas. DMG antennas may be used to create sectors in which the STA can transmit and receive frames. The number of sectors per DMG antenna cannot exceed 64. The total number of sectors across all DMG antennas of the STA cannot exceed 128.

[0167] SLS between the initiator and the responder is considered successful for the initiator when the initiator receives a response for the frame transmitted to the responder using the sector and antenna selected during SLS after the completion of SLS. It is considered successful for the responder when the responder receives a response for the frame transmitted to the initiator using the sector and antenna selected during SLS after the completion of SLS.

[0168] The SLS phase may include up to four components: an initiator sector sweep (ISS) for training initiator links, a responder sector sweep (RSS) for training responder links, an SSW feedback procedure, and an SSW verification procedure.

[0169] The ISS consists of an initiator transmission sector sweep (TXSS) or an initiator reception sector sweep (RXSS).

[0170] Figure 10 shows an example of an initiator TXSS and / or an initiator RXSS.

[0171] If the initiator has two or more DMG antennas, the initiator transmits BF frames through a number of sectors equal to the value of the field for the total number of sectors last negotiated transmitted to the responder. In each BF frame transmitted, the initiator sets the Sector ID and DMG Antenna ID fields to uniquely identify the sector and DMG Antenna ID used by the initiator for frame transmission, respectively, and sets the CDOWN field to the total number of transmissions remaining from all initiators' DMG antennas.

[0172] During the initiator TXSS (I-TXSS), the sector ID field of each BF frame must be set to a value that uniquely identifies the transmitting antenna sector used during the transmission of the BF frame. The CDOWN field of each transmission frame must contain the total number of transmissions remaining until the end of the initiator TXSS (including LBIFS if necessary), and the CDOWN field is set to 0 during the transmission of the last BF frame of the initiator TXSS. Each transmitted BF frame must be separated by a time interval equal to the SBIFS unless the allocation is terminated.

[0173] During the Initiator RXSS (I-RXSS), the initiator must transmit the number of BF frames indicated in the Last Negotiated RXSS Length field, which was transmitted by the responder from the selected DMG antenna and sector during the previous TXSS with the responder. Each transmitted BF frame must be transmitted to the same fixed antenna sector or pattern. The initiator must set the Sector ID and DMG Antenna ID fields of each transmitted BF frame to values ​​that uniquely identify the single sector in which the BF frame is transmitted. The initiator must set the total number of transmissions remaining until the end of the Initiator RXSS in the CDOWN field of each transmitted BF frame so that the CDOWN field is set to 0 upon the transmission of the last BF frame of the Initiator RXSS. Each transmitted BF frame must be separated by the same time interval as the SBIFS, except when the allocation ends.

[0174] During the initiator RXSS, the responder must configure the receiving antenna array to sweep the RXSS length sector, including LBIFS if necessary, while attempting to receive an SSW frame from the initiator.

[0175] The initiator RXSS is terminated with the CDOWN field set to 0 at the end time of the SSW frame sent by the initiator. If the responder does not receive this frame, the responder assumes that the initiator RXSS was completed at the expected end time of this frame.

[0176] RSS consists of responder TXSS or responder RXSS.

[0177] If the previous ISS was performed with at least one SSW frame, the responder initiates RSS by sending an SSW frame. If the previous ISS was performed with at least one Short SSW PPDU, the responder initiates RSS by sending a Short SSW PPDU.

[0178] Figure 11 shows the responder TXSS and / or responder RXSS.

[0179] During the responder TXSS (R-TXSS), the responder must set the Sector ID and DMG Antenna ID fields of each transmitted SSW frame to values ​​that uniquely identify the sector to which the SSW frame is being transmitted. The initial value of CDOWN is set to the responder's total number of sectors (including all DMG antennas) multiplied by the initiator's number of DMG antennas minus 1. The responder sets the CDOWN field of each transmitted SSW frame to include the total number of transmissions remaining until the end of the responder TXSS, including LBIFS if necessary, so that the CDOWN field is set to 0 upon the transmission of the last SSW frame of the responder TXSS. The responder transmits from the DMG antennas in increasing order of DMG Antenna ID. Each transmitted SSW frame is separated by a time interval equal to SBIFS. Transmissions are not separated by SBIFS if the allocation ends, the end of the SSW slot is reached, or the responder has completely swept all transmission sectors and is ready to transmit to another DMG antenna of the initiator. In the latter case, the next transmission is separated from the previous transmission by LBIFS.

[0180] During responder RXSS (R-RXSS), the responder must transmit the number of SSW frames indicated in the RXSS length field (non-A-BFT) or FSS field (A-BFT) most recently transmitted by the initiator from the DMG antenna and sector selected during the previous TXSS with the initiator. The responder must set the Sector ID and DMG Antenna ID fields of each transmitted frame to values ​​that uniquely identify the sector and DMG antenna, respectively, to which the BF frame was transmitted. The responder must set the total number of transmissions remaining until the end of the responder RXSS in the CDOWN field of each transmitted SSW frame so that the CDOWN field becomes 0 upon the transmission of the last SSW frame of the responder RXSS. Each transmitted SSW frame must be separated by the same time interval as SBIFS, except when the allocation ends or the end of the SSW slot is reached.

[0181] The responder must set the sector selection field and DMG antenna selection field of each transmitted SSW frame to the sector ID field and DMG antenna ID field values ​​of the frame received with the best quality during the ISS, respectively.

[0182] When responder RXSS starts, the initiator must configure the receiving antenna array to sweep the RXSS length sector, including LBIFS if necessary, when attempting to receive a frame from the responder until responder RXSS is completed.

[0183] Respondent RXSS is terminated at the end time of the SSW frame of the responder where the CDOWN field is set to 0. If the initiator cannot receive this frame, the initiator must assume that the responder RXSS was completed at the expected end time of this frame.

[0184] The SSW feedback procedure occurs after each RSS.

[0185] During the SSW feedback process, the initiator must send the SSW feedback frame to the respondent.

[0186] During the SSW feedback procedure, the responder must configure the receiving antenna array to the quasi-omni antenna pattern of the DMG antenna that received with the best quality during the ISS, or to the best antenna configuration found during the RXSS if the RXSS was performed during the ISS, and must not change the receiving antenna configuration when communicating with the initiator until the SSW feedback procedure concludes as expected.

[0187] If a responder TXSS consisting of SSW frames was performed during the previous RSS, the initiator must set the sector selection field and DMG antenna selection field of the transmitted SSW feedback frame to the sector ID field and DMG antenna ID field values ​​of the frame received at the highest quality during the responder TXSS, respectively. Determining which frame was received at the highest quality may vary depending on the implementation method. Additionally, the initiator must set the SNR report field to the measured SNR for the frame received from the sector and DMG antenna indicated in the sector selection field and DMG antenna selection field. The SSW-feedback frame must be transmitted through the sector identified by the sector selection field and DMG antenna selection field values ​​received from the responder during the previous responder TXSS.

[0188] If a responder TXSS consisting of a Short SSW PPDU was performed during the previous RSS, the initiator must transmit an SSW-Feedback frame through the sector identified by the Short SSW feedback field value received from the responder during the responder TXSS. In the SSW-Feedback frame, the initiator must set the EDMG extension flag subfield to 1, set the Sector Select and Sector Select MSB subfields to represent the CDOWN field value within the Short SSW PPDU received with the best quality during the responder TXSS, and set the DMG Antenna Select and DMG Antenna Select MSB subfields to the RF chain ID field value within the same Short SSW PPDU. This determination must be based on the reception quality measured at the DMG antenna used to transmit the current SSW-Feedback frame. Additionally, the initiator must set the SNR report field to the measured SNR for the PPDU received at the sector and DMG antenna specified in the Sector Select, Sector Select MSB, DMG Antenna Select, and DMG Antenna Select MSB subfields.

[0189] If responder RXSS (RXSS) was performed during the previous RSS (RSS), the Sector Select field and DMG Antenna Select field of the transmitted SSW-Feedback frame are reserved. The initiator must set the SNR reporting field to the SNR measured in the frame of the receiving sector specified in the RSS. The SSW-Feedback frame must be transmitted through the sector identified by the Sector Select field value received from the responder during the initiator and the most recently completed RSS (RSS).

[0190] The initiator may include transmission training as part of the beam refinement step by setting the TX-TRN-REQ field of the SSW Feedback frame to 1 and setting the L-RX field to specify the length of the training sequence requested for use by the responder during the beam refinement step. The initiator may perform the MIDC substep as part of the beam refinement by setting the BC-REQ field to 1 (request BC substep) and setting the MID-REQ field to 1 (request MID substep). In this case, the L-RX field must be set to indicate the number of received AWVs used by the initiator during the MID substep.

[0191] If the responder receives an SSW-Feedback frame from the initiator before completing the RSS with the initiator, the responder may stop the RSS.

[0192] If there is an SSW-Ack procedure, the SSW ack procedure is performed after the SSW feedback procedure.

[0193] If a responder TXSS is performed during RSS, the responder must send an SSW-Ack frame to the initiator to perform the SSW ack procedure. If the RSS is configured as an SSW frame, the SSW-Ack frame must be transmitted through the sector identified by the values ​​of the Sector Select field and DMG Antenna Select field received from the initiator in the last SSW-Feedback frame; if the RSS is configured as a Short SSW PPDU, it must be transmitted through the sector identified by the values ​​of the Sector Select subfield, Sector Select MSB subfield, DMG Antenna Select subfield, and DMG Antenna Select MSB subfield received from the initiator in the last SSW-Feedback frame. If the RSS is configured as a Short SSW PPDU, the Sector Select field and Sector Select MSB field of the SSW-Ack frame must be set to values ​​corresponding to the sector of the same initiator DMG antenna used to transmit the previous SSW-Feedback frame. The value must be based on the reception quality measured at the same DMG antenna used to transmit the current SSW-Ack frame and may correspond to a different sector from the sector indicated in the Short SSW Feedback field of the Short SSW PPDU transmitted during the RSS.

[0194] When an initiator TXSS consisting of a Short SSW PPDU with the Unassociated field set to 1 is executed during ISS, the Sector Select subfield, Sector Select MSB subfield, DMG Antenna Select subfield, and DMG Antenna Select MSB subfield of the SSW-Ack frame are ignored.

[0195] If RXSS is performed during RSS, the responder must send an SSW-Ack frame to the initiator. The SSW-Ack frame must be transmitted using the DMG antenna specified in the DMG Antenna Select field of the last SSW-Feedback frame.

[0196] The responder may include transmission training as part of the beam refinement phase by setting the TX-TRN-REQ field of the SSW-Ack frame to 1 and setting the L-RX field to specify the length of the training sequence that the initiator requests to use in the beam refinement phase. The responder may perform the MID substep by setting the MID-REQ bit to 1 in the BRP request field of the SSW frame. In this case, the responder must also set the L-RX field to indicate the number of received AWVs to use during the MID substep. The responder may perform the BC substep by setting the BC-REQ bit to 1. If the initiator sets either the MID-REQ or BC-REQ field to 1 in the SSW-Feedback frame, the responder may accept the request by setting either the MID-Grant or BC-Grant field to 1 or both.

[0197] If the RSS is composed of an SSW frame, at the start of the SSW ack procedure, the initiator must configure the receiving antenna array in a quasi-omni antenna pattern using the DMG antenna that received the highest quality during the RSS, or the best receiving sector if RXSS was performed during the RSS, and must not change the receiving antenna configuration while attempting to receive from the responder until the SSW ack procedure concludes as expected. If the RSS is composed of a Short SSW PPDU, at the start of the SSW ack procedure, the initiator must configure the receiving antenna array in a quasi-omni antenna pattern using the DMG antenna that was used for the previous SSW-Feedback frame transmission.

[0198] BRP is a process in which the STA trains RX and TX antenna arrays and improves the TX and RX antenna configurations through an iterative procedure. BRP can be used regardless of the antenna configurations supported by the STA.

[0199] The BRP stage consists of the BRP setup substage, the Multi-Sector ID Detect (MID) substage, the Beam Combine (BC) substage, a subset of the previous substages, and one or more Beam Refine transactions. Through BRP setup, the STA can exchange Beam Refine function information and request the execution of other BRP substages. MID and BC (collectively referred to as the MIDC substage) are optionally used to find better initial AWVs for iterative Beam Refine than might have been found in SLS due to incomplete quasi-omni receiving antenna patterns. In MID, quasi-omni transmitting patterns are tested against multiple receiving AWVs. This reverses the scanning role in the transmitting sector sweep. BC prevents the use of quasi-omni patterns by testing a small number of transmitting and receiving AWVs in pairs. Finally, once a starting point is established in SLS or MIDC, the STA can explore a broader set of transmitting and receiving AWVs using request / response frame exchanges known as Beam Refine transactions.

[0200] Meanwhile, MLDs defined in IEEE 802.11be have achieved significant improvements in terms of aggregate / average throughput and latency by including affiliated APs operating on one or more different channels. In particular, while existing MLDs were primarily set to a target band of 2.4 to 7.25 GHz (sub-7 GHz), the need for mmWave—which offers powerful throughput and latency improvements despite relatively limited coverage—has recently emerged. Consequently, MLDs are now being designed to include affiliated APs operating in the mmWave band, specifically the unlicensed bands between 42 and 71 GHz. Therefore, issues arising from the inclusion of affiliated APs in MLDs operating in the mmWave band need to be resolved.

[0201] Figure 12 shows examples of AP MLD and Non-AP MLD that support the mmWave band.

[0202] Referring to Fig. 12, AP 1 of the AP MLD operates a channel in the Sub-7GHz band and AP 3 operates a channel in the mmWave band, and STA 1 of the Non-AP MLD supports the Sub-7GHz band and STA 2 supports the mmWave band. Therefore, the Non-AP MLD can request a multi-link setup from the AP MLD so that STA 1 can be associated with AP 1 (Link 1) and STA 2 can be associated with AP 3 (Link 2).

[0203] To this end, basically, in a multi-link operation (MLO), at least the procedure exemplified in FIG. 13 can be performed.

[0204] Figure 13 shows an example of a multi-link discovery and multi-link setup procedure.

[0205] Referring to FIG. 13, in step S1001, the Non-AP MLD can detect / identify the presence of the AP MLD through a scanning process by receiving a Beacon or transmitting a Probe Request frame. In particular, one of the AP MLD's associated APs (e.g., AP 1 in FIG. 13) can include a Basic Multi-link element (Basic ML IE) in the Beacon or Probe Response frame to indicate that it belongs to the AP MLD and provide some information about it.

[0206] In step S1003, the Non-AP MLD discovers AP 1 and may request information about one or more other associated APs of the AP MLD to which AP 1 belongs from AP 1. At this time, information about one or more other associated APs of the AP MLD to which AP 1 belongs may be requested using an ML Probe Request, which is a Probe Request frame containing a Probe Request ML element (Probe Request ML IE).

[0207] In step S1005, AP 1 (or AP MLD) that receives the ML Probe Request may transmit an ML Probe Response, which is a Probe Response frame containing Basic ML IE, in response thereto. At this time, based on the request information, AP 1 may include a Partial profile or a complete profile for one or more other associated APs.

[0208] In step S1007, the Non-AP MLD may select an appropriate AP based on information about one or more associated APs of the AP MLD and request a multi-link setup from AP 1. At this time, the Non-AP MLD may transmit an Association Request frame containing a Basic ML IE. The Basic ML IE may include information such as which AP each associated STA of the non-AP MLD wishes to connect to, and / or the complete profile of each requesting associated STA.

[0209] In step S1009, the AP MLD that received the request for multi-link configuration determines whether to accept or reject which STA and AP can be connected based on the information of the STAs associated with the Non-AP MLD, and can transmit an Association Response frame. At this time, the Association Response frame may include a Basic ML IE containing information such as a Status Code indicating acceptance or rejection and / or a complete profile for each requested associated AP.

[0210] Meanwhile, an AP MLD can assign a single common AID to a Non-AP MLD. For example, an AP MLD can assign an AID with a value between 1 and 245 to a DMG STA and an AID with a value of 0 to an AP or PCP. On the other hand, an AP MLD with a link in the sub-7GHz band can assign a common AID with a value between 1 and 2007 to a Non-AP MLD. Therefore, when allocating a specific interval for Beamforming Training (BFT) and / or data frame exchange in the mmWave band and assigning specific STAs within that interval based on AID, a problem may arise.

[0211] Accordingly, the present disclosure provides an AID allocation method for MLDs having mmWave bands and / or requirements therefor.

[0212] Meanwhile, the mmWave band is characterized by the need for directional transmission due to its relatively small communication distance / coverage, which can increase the complexity of protocols / implementations for beamforming and / or control / management. Therefore, as illustrated in the procedure in Fig. 13, if an STA operating in the sub-7GHz range (e.g., STA 1) can perform control / management tasks instead of an STA operating in the mmWave band, the mmWave band can be utilized more efficiently. In particular, BFT is required between the STA and the AP, which is one of the essential elements for directional transmission in the mmWave band. While frame exchange for BFT can be performed in the mmWave band, the period for BFT and announcement / negotiation of related parameters can be performed in the sub-7GHz band to reduce the control / management overhead for BFT in the mmWave band.

[0213] Accordingly, the present disclosure provides a method for controlling / managing phases and / or related parameters for BFT in the mmWave band at Sub-7 GHz. In particular, BFT may include a Sector Level Sweep (SLS) phase and / or Beam Refinement Protocol (BRP) in IEEE 802.11ad / 11ay. The present disclosure provides a method for managing phases and / or related parameters for the SLS phase at Sub-7 GHz. Embodiments of the present disclosure may be applied to beamforming training methods such as the SLS phase and / or other beamforming training methods such as BRP.

[0214] In the present disclosure, a STA or AP operating in the mmWave band belonging to the same MLD is referred to as mSTA or mAP, respectively, and a STA or AP operating in the sub-7GHz band is referred to as sSTA or sAP, respectively. Additionally, an MLD having an mSTA or mAP is referred to as an Integrated mmWave MLD (IMMW MLD).

[0215] Designations (names) in this disclosure may be changed, and STA may include AP STA and / or non-AP STA. Additionally, MLD may include AP MLD and / or non-AP MLD.

[0216] FIG. 14 illustrates an example of a method performed on an AP MLD in a scheduling procedure for frame switching in a high-frequency band according to an embodiment of the present disclosure.

[0217] Referring to FIG. 14, in step S1401, the first AP associated with the AP MLD and related to the first frequency band can transmit information to one or more other APs associated with the AP MLD and related to the second frequency band higher than the first frequency band.

[0218] In step S1403, the first AP may receive one or more request frames to request a connection between the second AP and one or more STAs among one or more other APs. Each of the one or more STAs is associated with a corresponding non-AP MLD and may be associated with a second frequency band.

[0219] In step S1405, the first AP can transmit one or more response frames for one or more request frames.

[0220] In step S1407, the first AP may transmit scheduling information for the second AP. The scheduling information may include at least one of i) identification information for an initiator among the STAs associated with the second AP who initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP who performs frame exchange with the initiator, or iii) information for a time interval for frame exchange. The STAs associated with the second AP may include the second AP and one or more STAs connected to the second AP.

[0221] According to various embodiments, identification information for an initiator may include at least one of an identifier (ID) of an initiator, information indicating whether a second AP is an initiator, or information indicating whether any STA among the STAs associated with the second AP can be an initiator.

[0222] According to various embodiments, the identifier of the initiator may be set to a value indicating the STA that is the initiator among the STAs associated with the second AP, or a value indicating that any STA among the STAs associated with the second AP can be the initiator.

[0223] According to various embodiments, the identifier of the initiator may be omitted based on the fact that the identification information for the initiator includes information indicating that the second AP is the initiator.

[0224] According to various embodiments, the identifier of the initiator may be omitted based on the fact that the identification information for the initiator includes information indicating that any STA among the STAs associated with the second AP may be the initiator.

[0225] According to various embodiments, identification information for at least one respondent may include at least one of the respondent's identifier, or information indicating whether all STAs connected to the initiator among the STAs associated with the second AP are respondents.

[0226] According to various embodiments, the respondent identifier may be set to a value indicating a respondent STA among the STAs associated with the second AP, or a value indicating that all STAs connected to the initiator among the STAs associated with the second AP are respondents.

[0227] According to various embodiments, the identifier of the respondent may be omitted based on the fact that the identification information for at least one respondent includes information indicating that all STAs connected to the initiator among the STAs associated with the second AP are respondents.

[0228] According to various embodiments, information regarding a time interval may include at least one of information regarding the start time of the time interval, information regarding the length of the time interval, or information regarding the interval between consecutive time intervals.

[0229] According to various embodiments, the scheduling information may further include information regarding the frequency / channel for frame switching.

[0230] According to various embodiments, information regarding frequency / channel may include at least one of information regarding bandwidth for frame switching or an index of a channel associated with bandwidth.

[0231] According to various embodiments, frame exchange may include data frame exchange.

[0232] According to various embodiments, frame exchange may include frame exchange for beamforming training (BFT). The time interval may include the duration of the SLS phase.

[0233] According to various embodiments, the scheduling information may further include at least one of information regarding the SLS type, information regarding beamforming parameters, information regarding the number of sectors for BFT / SLS, information regarding the number of transmitting antennas for BFT / SLS, information regarding the number of receiving antennas for BFT / SLS, information regarding the length of the Receive Sector Sweep (RXSS), or an identifier (ID) of the corresponding SLS stage. The SLS type may include at least one of an initiator Transmit Sector Sweep (I-TXSS), an initiator Receive Sector Sweep (I-RXSS), a responder TXSS (R-TXSS), or a responder RXSS (R-RXSS).

[0234] According to various embodiments, the first frequency band may be a sub-7 GHz band. The second frequency band may be a high frequency band (e.g., a millimeter wave (mmWave) band).

[0235] FIG. 15 illustrates an example of a method performed by a non-AP MLD in a scheduling procedure for frame switching in a high-frequency band according to an embodiment of the present disclosure.

[0236] Referring to FIG. 15, in step S1501, a first STA associated with a non-AP MLD and associated with a first frequency band can receive information about one or more other APs associated with an AP MLD and associated with a second frequency band higher than the first frequency band from a first AP associated with an AP MLD and associated with a first frequency band.

[0237] In step S1503, the first STA may transmit a request frame to request a connection between the second STA associated with the second frequency band and the second AP and non-AP MLD among one or more other APs.

[0238] In step S1505, the first STA can receive a response frame for a request frame.

[0239] In step S1507, the first STA may receive scheduling information for the second AP from the first AP. The scheduling information may include at least one of i) identification information for an initiator among the STAs associated with the second AP who initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP who performs frame exchange with the initiator, or iii) information for a time interval for frame exchange. The STAs associated with the second AP may include the second AP and one or more STAs connected to the second AP.

[0240] In FIG. 15, the first AP exchanges one request frame / one response frame with one non-AP MLD, but this is exemplary, and as in FIG. 14, the first AP can exchange one or more request frames / one or more response frames. That is, the first AP in FIG. 15 can also perform the same operation as in FIG. 14.

[0241] According to various embodiments of the present disclosure, a first STA (e.g., a first AP of FIG. 14, 15) may transmit one or more scheduling information for one or more STAs (e.g., one or more APs of FIG. 14, 15) within an MLD to which it belongs (e.g., an AP MLD of FIG. 14, 15) via one or more PPDUs. The one or more scheduling information may include scheduling information for frame switching and / or scheduling information for SLS.

[0242] The first STA (e.g., the first AP of the AP) may be an associated AP (sAP) operating in the sub-7GHz band of the AP MLD, and one or more STAs corresponding to the scheduling information (or, SLS scheduling information) may be associated APs (mAPs) operating in the mmWave band.

[0243] One or more PPDUs may include a Beacon frame, a Probe Response frame, and / or an Association Response frame. Additionally, or alternatively, a separate frame (e.g., an Action frame) may be defined and included in the PPDU.

[0244] Frame exchange may include at least one of beamforming training and / or data frame exchange.

[0245] Scheduling information (or SLS scheduling information) may include time / frequency information and / or identification information.

[0246] For example, time / frequency information may include period timing information. Period Timing Information may include time information for a schedule (e.g., start time, duration, interval between consecutive periods).

[0247] For example, time / frequency information (or SLS time / frequency information) may include SLS time information. SLS time information may include information on when an SLS phase / interval starts, how long it lasts, and at what interval it is repeated.

[0248] For example, the identification information may be SLS identification information. The SLS identification information may include a set of IDs to distinguish each SLS phase. The SLS identification information may include an ID that distinguishes the scheduling for each SLS phase.

[0249] For example, the identification information may include identification information for an initiator initiating frame exchange / BFT, and / or identification information for a responder performing frame exchange / BFT with the initiator.

[0250] For example, identification information for the initiator may include an initiator ID (i.e., the ID of the STA corresponding to the initiator). Identification information for the respondent may include a respondent ID (i.e., the ID of the STA corresponding to the respondent).

[0251] For example, the initiator ID may be the Source AID and the responder ID may be the Destination AID. The Source AID may be the AID of a STA corresponding to at least one STA in a specific interval. The Destination AID may be the AID of a STA corresponding to at least one responder capable of performing frame exchange with the initiator.

[0252] For example, the initiator ID may be the ID of a STA corresponding to at least one initiator in each SLS Phase. The responder ID may be the ID of a STA corresponding to at least one responder capable of performing frame exchange with the initiator in each SLS Phase.

[0253] For example, the initiator ID and responder ID can be composed of an X-bit field (e.g., AID field) (e.g., X=12, 11, 7).

[0254] For example, the initiator ID and responder ID may include a Broadcast AID having a specific AID value (e.g., 2044, 2045, 255).

[0255] For example, the scheduling information / initiator identification information may include a field indicating that if the AP or PCP becomes the Source / initiator, it transmits the frame first or triggers mSTAs. In this case, the initiator ID may not be included in the scheduling information / initiator identification information.

[0256] For example, scheduling information / identification information may include a field indicating that at least one STA or all STAs can participate in a specific interval / each SLS phase as an initiator or responder. In this case, the responder ID may not be included in the scheduling information / identification information. This field may include subfields applicable to the Source and Destination, respectively.

[0257] Scheduling information (or SLS scheduling information) may further include SLS BFT information. SLS BFT information may include information necessary for performing BFT.

[0258] For example, SLS BFT information may include type information capable of distinguishing I-TXSS, I-RXSS, R-TXSS, R-RXSS, etc.

[0259] For example, SLS BFT information may include information on the Number of Sectors and / or information on the TX / RX DMG Antenna. Information on the Number of Sectors and / or information on the TX / RX DMG Antenna may be determined by STAs that may be initiators or respondents during the pre-negotiation process.

[0260] For example, SLS BFT information may include RXSS Length information for RXSS.

[0261] According to various embodiments, a second STA (e.g., the first STA in FIG. 15) receives a frame containing one or more scheduling information (e.g., scheduling information for frame exchange / SLS phase related scheduling information) for one or more other STAs (e.g., one or more other APs in FIG. 14 and 15) within an MLD to which the first STA belongs (e.g., the first AP in FIG. 14 and 15) from a first STA (e.g., the first AP in FIG. 15), and can perform frame detection and obtain scheduling information for each STA in the MLD to which the first STA belongs through frame detection. The second STA can verify scheduling information for one or more other STAs in the MLD to which the first STA belongs through the obtained scheduling information.

[0262] The first STA can be an associated AP (sAP) operating in the sub-7GHz band of the AP MLD, and one or more STAs corresponding to the scheduling information can be associated APs (mAPs) operating in the mmWave band.

[0263] The second STA may be an associated STA operating in the sub-7GHz band of the MLD. At least one associated STA operating in a different mmWave band of the MLD to which the second STA belongs may perform frame switching / BFT based on scheduling information.

[0264] Below, a detailed implementation for scheduling frame switching in a high-frequency band (e.g., mmWave band) is described.

[0265] Unlike the requirements of the DMG, the IMMW MLD can be assigned an AID with a single value within the range of 1 to 2007. Additionally, the IMMW MLD can assign a specific interval capable of exchanging BFT / data frames over the mmWave band and at least one STA. In this case, an AID assignment method capable of distinguishing the STAs is required.

[0266] Accordingly, an AID allocation method capable of distinguishing STAs is described below. In this disclosure, a STA that initiates frame exchange in a TXOP and / or specific interval may be referred to as the initiator, and a STA that performs frame exchange with the initiator may be referred to as the responder. Additionally, the meaning of “AID allocation for mSTA” may be interpreted as having the same meaning as “AID allocation for IMMW MLD.”

[0267] 1) Source AID and Destination AID

[0268] Source AID may refer to the AID of a STA corresponding to at least one initiator in a specific interval. Destination AID may refer to the AID of a STA corresponding to at least one responder capable of performing frame exchange with the initiator.

[0269] When specifying the AID for the mSTA / IMMW MLD and the specific period in which mSTAs will operate, the AID may be specified in at least one of the following ways on a link in the sub-7 GHz band and / or a link in the mmWave band. The meaning of the X-bit AID field (referred to as the AIDX field below) may mean, but is not limited to, “12 LSB (least significant bits) of the STA’s AID” in the AID field specified in the Association Response frame.

[0270] Method 1-1) When assigning an AID to an mSTA / IMMW MLD from the AID range assigned to an existing STA / Non-AP MLD (i.e., AID = [1:2007]), the AID assigned to an MLD with an mSTA may have at least 11 bits.

[0271] For example, the AID can be indicated via the AID11 field. Additionally, or alternatively, if a value greater than 2047 (e.g., one example of a Broadcast AID below) is required, the AID can be indicated via the AID12 field.

[0272] This method is easy to implement because it maintains the existing range.

[0273] Method 1-2) When assigning an AID to an mSTA / IMMW MLD for a specific range within an existing range, the AID specified for the IMMW MLD may be specified with a range-based size (e.g., [X:Y]). In this case, the size may be determined based on the maximum value, Y. Additionally, or alternatively, an AID range based on the maximum number (N) of multiple BSSID sets may be excluded (i.e., 1-N). For example, if Y is 100, the AID7 field may be configured. In this case, the IMMW AP MLD may not assign an AID of this range to an MLD / STA that is not an IMMW MLD.

[0274] This method can reduce overhead when directing a specific STA.

[0275] Method 1-3) When assigning an AID to an mSTA / IMMW MLD for a specific range other than the existing range, the AID indicating the MLD with the mSTA / IMMW MLD may be set to a value within the range of 2007 onwards, i.e., 2008-Y. In this case, the size may be determined based on the maximum value, Y. The field indicating such an AID may be an AID11 field or an AID12 field having at least 11 bits, similar to method 1-1).

[0276] This method may not affect AID assignments for existing STAs (e.g., IEEE 802.11 ac / ax / be STA).

[0277] Additionally or alternatively, the AID corresponding to the AP or PCP can be set to 0 or a value after 2007 (e.g., 2010, 2044).

[0278] FIG. 16 shows an example of scheduling based on AID assignment. In FIG. 16, the initiator may be an AP and the responder may be a STA.

[0279] Referring to FIG. 16, the sAP can transmit scheduling information via the Beacon (B) to the BSS of mAP 1, along with information about a specific period (e.g., Period Timing Info), and via the AID12 field, to instruct the AP (Source AID = 0) as the initiator and mSTA 2 (Destination AID = 200) as the responder to operate during that period. Additionally or alternatively, the Beacon (B) may be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field may be replaced with AID11, AID7, etc., based on the method described above.

[0280] Since the Source (or initiator) is mAP 1, mAP 1 can first transmit a frame to exchange frames with mSTA 2, and mSTA 2 can wait for a frame from the AP because it knows that it is the responder. For example, mSTA 2 may be in an awake state before the relevant period (e.g., the period indicated by Period Timing Info) begins. Here, mAP 1 can transmit a frame based on at least one channel access method. For example, mAP 1 can perform back-off via EDCA and / or determine whether to transmit a frame via CCA during the PIFS period based on the Start time of the relevant period, and if the channel is IDLE, it can transmit the frame.

[0281] Additionally or alternatively, when an AP or PCP becomes the Source, it may be indicated by a field meaning that it first transmits a frame or triggers mSTAs. In this disclosure, such a field may be referred to as the trigger field. For example, when the trigger field is enabled (e.g., trigger field = 1), it may indicate that when an AP or PCP becomes the Source, it first transmits a frame or triggers mSTAs. In this case, overhead can be reduced because the Source AID may not exist, and an example thereof is illustrated in FIG. 17.

[0282] FIG. 17 illustrates an example of scheduling based on a trigger field. In FIG. 17, the initiator is AP, the responder is STA, and the scheduling information may include a trigger field.

[0283] Referring to Fig. 17, mAP 1 and mSTA 2 can see through the trigger field that the Source (initiator) is mAP 1. Additionally, or alternatively, if the trigger field is enabled (e.g., trigger field = 1), the Source AID12 field may not exist.

[0284] 2) Broadcast AID

[0285] A Broadcast AID may be assigned to a Source AID and a Destination AID, but is not limited thereto. A Broadcast AID may mean that at least one mSTA can be the initiator in a specific interval and / or there may be at least one mSTA (e.g., all mSTAs) capable of performing frame exchange with the initiator. For example, if the Source AID is a Broadcast AID, the STA that acquired the TXOP in a channel access interval capable of performing random back-off, such as EDCA, may be the initiator. As another example, if the STA corresponding to the Source AID is an AP or PCP and the Destination AID is a Broadcast AID, at least one mSTA (e.g., all mSTAs) may be waiting to receive a frame from the AP or PCP in an awake state.

[0286] In some implementations, the Broadcast AID may be set to a specific value. For example, the Broadcast AID may be set to 0 or 2007 followed by a value e.g., 2010, 2044. Additionally or alternatively, if the AID12 field is used, the AID12 values ​​2045, 2046 used in the trigger frame may also be used when transmitting a frame that is not a trigger frame (e.g., when indicating the AID in this disclosure).

[0287] The Broadcast AID can be an AID value that is not assigned to MLD / STA.

[0288] Additionally or alternatively, if the value 255 used in the DMG is used, the IMMW AP MLD must not assign 255 as AID to MLD / STA other than the IMMW MLD.

[0289] FIG. 18 illustrates an example of scheduling based on a Broadcast AID. In FIG. 18, the initiator is an AP, and the responder may be at least one STA (or all STAs).

[0290] Referring to FIG. 18, the sAP can transmit scheduling information via the Beacon (B) to the BSS of mAP 1, along with information about a specific period (e.g., Period Timing Info), and via the AID12 field, to instruct the AP (Source AID=0) as the initiator and all STAs (Destination AID=2044, Broadcast AID) as the responders to operate in that period. Additionally or alternatively, the Beacon (B) can be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field can be replaced with AID11, AID7, etc., based on the method described above. If AID7 is used, the Broadcast AID can have a value of 255.

[0291] Since the Source (or initiator) is mAP 1, mAP 1 may first optionally transmit a frame for frame exchange with mSTA 1, as the Destination (or responder) can be any STA. mSTA 1 and mSTA 2 may wait for a frame from the AP because they know they can be responders. For example, mSTA 1 and mSTA 2 may be in an awake state before the relevant period (e.g., the period indicated by Period Timing Info) begins. Here, mAP 1 may transmit a frame based on at least one channel access method. For example, mAP 1 may perform back-off via EDCA and / or determine whether to transmit a frame via CCA during the PIFS period based on the Start time of the relevant period, and transmit the frame if the channel is IDLE. In this example, the frame is transmitted only to mSTA 1, but mAP 1 may transmit the frame to mSTA 1 or to both mSTA 1 and mSTA 2 depending on the situation.

[0292] Additionally or alternatively, the scheduling information may include a field indicating that at least one STA or all STAs can participate in a specific interval. In the present disclosure, such a field may be referred to as a Broadcast field. In this case, overhead may be reduced because a Destination AID may not exist.

[0293] FIG. 19 illustrates an example of scheduling based on a Broadcast field. In FIG. 19, the initiator is an AP, the responder is at least one STA (or all STAs), and the scheduling information may include a Broadcast field.

[0294] Referring to FIG. 19, the scheduling information may include a Broadcast field. Through the Broadcast field, mAP 1, mSTA 1, and mSTA 2 can know that all STAs can participate as Destination (responders). For example, if the Broadcast field is enabled (e.g., Broadcast field = 1), this may indicate that all STAs can participate as Destination (responders). Additionally, or alternatively, if the Broadcast field is enabled (e.g., Broadcast field = 1), the Destination AID12 field may not exist.

[0295] FIG. 20 illustrates an example of scheduling based on a trigger field / broadcast field. In FIG. 20, the initiator is an AP, the responder is at least one STA (or all STAs), and the scheduling information may include a trigger field / broadcast field.

[0296] Referring to FIG. 20, the scheduling information may include a Source AID12 field / Destination AID12 field set to a Broadcast AID (2044), a trigger field, or at least one of a Broadcast field. Even if the Source AID12 field is a Broadcast AID, if the trigger field is enabled (e.g., trigger field = 1), this may indicate that the AP can send the frame first. Additionally or alternatively, if the Source AID12 field is a Broadcast AID and / or the trigger field is enabled, this may not mean that mSTAs must always wait for the AP's frame.

[0297] Additionally or alternatively, the Broadcast field may be utilized for the Source AID with the same meaning as for the Destination AID. For example, the Broadcast field may include at least one of the Broadcast field corresponding to the Source AID (referred to as the Source Broadcast field) or the Broadcast field corresponding to the Destination AID (referred to as the Destination Broadcast).

[0298] FIG. 21 shows an example of scheduling when the Source AID / Destination AID is a Broadcast AID. In FIG. 21, the initiator may be at least one STA (or all STAs), and the responder may be at least one STA (or all STAs).

[0299] Referring to FIG. 21, the sAP can transmit scheduling information via the Beacon (B) to the BSS of mAP 1, along with information about a specific period (e.g., Period Timing Info), and via the AID12 field, to instruct all STAs (Source AID = 2044, Broadcast AID) as initiators and all STAs (Destination AID = 2044, Broadcast AID) as responders to operate in that period. Additionally or alternatively, the Beacon (B) can be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field can be replaced with AID11, AID7, etc., based on the method described above. If AID7 is used, the Broadcast AID can have a value of 255.

[0300] Since the Source (initiator) and Destination (responder) can be any STA, the STA that first occupies the channel via channel access (e.g., mSTA 2) can transmit the frame to the AP. Here, mSTA 2 can transmit the frame based on at least one channel access method. For example, mSTA 2 can perform back-off via EDCA and / or determine whether to transmit the frame via CCA during the PIFS interval based on the Start time of that interval, and if the channel is IDLE, it can transmit the frame.

[0301] Additionally or alternatively, scheduling information may include a Source Broadcast field and / or a Destination Broadcast field. Through the Source Broadcast field / Destination Broadcast field, mAP 1, mSTA 1, and mSTA 2 can know that all STAs can participate as Source (initiator) and Destination (responder). For example, if the Source Broadcast field is enabled (e.g., Source Broadcast field = 1), this may indicate that all STAs can participate as Source (initiator). For example, if the Destination Broadcast field is enabled (e.g., Destination Broadcast field = 1), this may indicate that all STAs can participate as Destination (responder).

[0302] Additionally or alternatively, if the Source Broadcast field is enabled (e.g., Source Broadcast field = 1), the Source AID12 field may not exist. If the Destination Broadcast field is enabled (e.g., Destination Broadcast field = 1), the Destination AID12 field may not exist.

[0303] Meanwhile, a BFT period (BFTP) and / or related parameters that may include an SLS Phase announced at sub-7GHz may include at least one of the following:

[0304] - Common Info for BFT: Information commonly applicable to all links operating in the mmWave band; and / or

[0305] - Per-link Info for BFT: Information specific to each link operating in the mmWave band.

[0306] Figure 22 shows an example of an announcement for BF.

[0307] Referring to FIG. 22, the sAP may transmit an Announcement frame (AF) containing “Common Info for BF / BFT” common to all mAPs and / or “Per-link Info for BF / BFT (e.g., BF interval / parameters)” specific to each mAP (e.g., mAP 1). For example, the AF may be a Beacon frame, Probe Response frame, or Association Response frame transmitted periodically as shown in FIG. 22. Additionally or alternatively, the AF may be defined as a separate frame (e.g., Action frame) to convey information about the BF. Additionally or alternatively, the AF is not limited to transmission by the AP; that is, it may also be transmitted by the STA.

[0308] In the present disclosure, an mSTA that initiates beamforming training (BFT) in a BFTP including an SLS Phase is referred to as a BFT initiator, and at least one mSTA that performs BFT with the BFT initiator is referred to as a BFT responder.

[0309] Information about the SLS Phase (or scheduling information about the SLS Phase) may include at least one of the following:

[0310] 1) SLS time information (or, SLS Time): Time information such as when the SLS Phase (interval) starts and how long it lasts can be indicated.

[0311] 2) SLS Beamforming Training Information (or, SLS BFT): Information required to perform BFT during the SLS Phase.

[0312] 3) SLS Identification Information: A set of IDs to distinguish each SLS Phase.

[0313] 4) SLS Channel (or Frequency) Information

[0314] At least one piece of information described below is not limited to SLS and may also be applied to other BFT steps, such as BRP, and / or steps for data frame transmission, etc.

[0315] I. SLS Time / Channel Information (or, SLS Time / Frequency Information)

[0316] SLS time / frequency information may include at least one of SLS time information or SLS frequency information.

[0317] SLS time information conveys SLS schedule (time) information of a beamforming interval (or BFTP) and may include at least one of an SLS start time (ST), an SLS duration, or an SLS interval.

[0318] - SLS ST: The point at which an SLS Phase begins.

[0319] SLS ST can be defined using the full / entire timestamp (e.g., TSF (timing synchronization function)) (i.e., 8 octets) and / or partial TSF of the AP transmitting this information. Partial TSF can be indicated using some bits of the 64 bits of the TSF (e.g., [10:25], [20:35], the first 4 octets).

[0320] Additionally or alternatively, the SLS ST can be defined in a TBTT offset format. For example, the SLS ST can indicate the difference (i.e., (TBTT) offset) in TU units from the time when the SLS starts (e.g., when the frame initiating the SLS is transmitted) from the Beacon currently transmitting this information. For example, if the offset is 1.3 TU, the SLS ST can indicate 1 TU through rounding down. This allows the receiving STA to receive the initiation frame in the SLS Phase while accounting for a certain amount of error.

[0321] - SLS Period: The duration of one SLS Phase.

[0322] The SLS period can be specified in specific units (e.g., 1 µs, 64 µs, 256 µs, 1 TU). Specific units can be specified in a separate field (e.g., 1 bit, 2 bits).

[0323] Additionally or alternatively, the SLS period may indicate a minimum and / or maximum value.

[0324] Additionally, the SLS period can have X bits / octets (e.g., 5 bits, 1 octet, 2 octets).

[0325] - SLS Interval: The interval between consecutive SLS Phase periods. For example, it may indicate the interval between the start (or end) of one SLS Phase and the start (or end) of the next SLS Phase.

[0326] Figure 23 shows an example of SLS time information.

[0327] For example, as shown in A of Fig. 23, when an SLS Phase period occurs periodically, the SLS interval between the starting points of each SLS Phase can be.

[0328] If the SLS interval is 0, this may mean that only one SLS phase occurs. For example, in A of Fig. 23, only the left SLS phase may occur.

[0329] For example, as shown in Fig. 23B, when one SLS Phase ends, the next SLS Phase can start immediately.

[0330] For example, as shown in Fig. 23C, other periods (e.g., BRP Phase periods) may follow in addition to the SLS Phase. The aforementioned BRP Phase period is an example of other periods, and in this disclosure, other periods are not limited to the BRP Phase period.

[0331] Additionally or alternatively, the periodic repetition of the SLS Phase can be limited by the SLS Number (i.e., the number of repeated SLS Phases). For example, if the number of SLS Phases (i.e., the SLS Number) is represented by X bits (e.g., X = 4, 8) and the SLS Number = 2, then no further SLS Phases may occur after 2 SLS Phases in A of FIG. 23. Each time an SLS Phase is performed, the value of the SLS Number may decrease by 1.

[0332] Additionally or alternatively, if the SLS Number is 1, the SLS interval field may be reserved or not exist.

[0333] Additionally or alternatively, a time gap between the SLS ST and the Announcement frame may be indicated. Specifically, the time gap may be the gap between the start or completion of transmission of the SLS ST and the Announcement frame. For example, the time gap may have X bits (e.g., 5 bits, 8 bits, etc.) to indicate the gap time, and may be indicated in a specific unit (e.g., 1 µs, 64 µs, etc.). In this case, the time gap may be identified in the mmWave band by considering the “case where the SLS ST is indicated by the TSF (described below).”

[0334] Additionally or alternatively, if a response frame (e.g., Ack) exists for an announcement frame, the time gap may be the gap between the start or completion time of transmission of the SLS ST and the response frame.

[0335] Additionally or alternatively, Announcement frames (e.g., request frames) and / or response frames can be Action frames. Additionally or alternatively, Announcement frames and / or response frames can be Control frames. In this case, the interval between the Announcement frame and the response frame can be SIFS.

[0336] Figure 24 shows an example of a case where BFTP is indicated based on the time gap.

[0337] Referring to Fig. 24, the Time Gap may be the gap from the time the transmission of AF is completed to SLS ST (example above). In this case, AF may be transmitted via Broadcast (e.g., Group-addressed) or unicast.

[0338] Alternatively, the Time Gap can be the gap from the completion of transmission of the response frame to the AF to the SLS ST (see example below); in this case, the AF can be transmitted as Unicast (e.g., Individually-addressed).

[0339] The time gap can be indicated based on at least one of the following methods:

[0340] Method 1) Pre-determined Time Gap

[0341] STA can be instructed on the Time Gap through management frames (e.g., Beacon frames, Probe Request / Response frames, Association Request / Response frames). Based on this Time Gap, STA can determine the start time of BFTP based on Announcement frames and / or Response frames.

[0342] Additionally or alternatively, Time Gap may be specified for AP (or AP MLD) and STA (or Non-AP MLD). In this case, the start time of BFTP may be considered based on the larger value of Time Gap.

[0343] Method 2) Instructions in the Announcement Frame

[0344] STA can provide a Time Gap through an Announcement frame. Based on this Time Gap, the start time of BFTP can be determined based on the Announcement frame and / or Response frame.

[0345] Additionally or alternatively, method 1) and method 2) may be used together. In this case, the Time Gap indicated through the Announcement frame may be indicated based on the Time Gap in the management frame in method 1). That is, the Time Gap indicated in 1) is the minimum required Time Gap, and the Time Gap in the Announcement frame may be set / indicated to a value at least equal to or greater than this.

[0346] ● When SLS ST is indicated as TSF

[0347] In some implementations, the SLS ST can be indicated using the TSF. However, if periodic Beacon transmissions containing the TSF are not performed in the mAP, the TSF setting for the mAP may not be clear. That is, although the sAP provides the SLS service period (SP) for the mAP, when the start time of the SP is based on the TSF, a method may be needed for the non-AP MLD to interpret the BFTP SP in the mAP based on the information provided by the sAP. Therefore, the sAP can indicate the BFTP SP using at least one of the methods described below.

[0348] If the TSF of mAP is not announced in mAP, sAP may provide information about the TSF of mAP. That is, the TSF for mAP may be indicated. Additionally or alternatively, this TSF may be considered as a virtual TSF. In this disclosure, the TSF for mAP may be referred to as mTSF.

[0349] The Non-AP MLD can determine the TSF offset between the mTSF and the TSF of at least one sAP through a Multi-link Probe Request / Response exchanged between the Non-AP MLD and the transmitting sAP transmitting this information, and / or the TSF offset between the mTSF and the TSF of at least one sAP can be transmitted continuously / periodically from the transmitting sAP's Beacon, etc. Accordingly, the SLS ST can be indicated based on at least one of the following methods:

[0350] 1) SLS ST is indicated based on mTSF

[0351] SLS ST is indicated based on mTSF, so Non-AP MLD can determine / identify SLS ST based on the sAP transmitting information about the SLS Phase and the TSF offset between the corresponding mAP.

[0352] Additionally or alternatively, the TSF of the mAP may be configured to have the same TSF as at least one other sAP. To this end, the sAP may include a link ID for the sAP having the same TSF in Common Info for the BFT and / or Per-link Info for the BFT corresponding to the mAP. Additionally or alternatively, if there are multiple sAPs having the same TSF, a link ID bitmap may be included to indicate the link IDs for those multiple sAPs. In this case, the Non-AP MLD may determine / identify the SLS ST based on the TSF offset with at least one sAP (which may include the transport sAP) having the same TSF as the transport sAP / mAP.

[0353] 2) SLS ST is indicated based on the TSF of the transmitting sAP

[0354] The SLS ST can be indicated based on the TSF of the sAP transmitting this information. In this case, the Non-AP MLD can determine / identify the SLS ST based on the acquired “TSF offset between the transmitting sAP and the corresponding mAP”.

[0355] Additionally or alternatively, the TSF offset between the transmission sAP and the corresponding mAP may be specified for the calculation of the accurate SLS ST.

[0356] If both ST and TSF offset are considered to be of the same size (e.g., both ST and TSF offset are 8 octets (or 2 octets)), the TSF offset can be added when calculating ST. However, if ST and TSF offset are of different sizes, ST needs to be calculated based on TSF. For example, if ST is 2 octets (e.g., Partial TSF [10:25]) and the TSF offset is 8 octets, ST can be calculated by first changing ST to the same size unit as the TSF offset (i.e., changing ST to 8 octets of TSF) and then adding the TSF offset.

[0357] - SLS Channel: Information about the channel on which SLS is performed. The channel may vary depending on channelization in the mmWave band. The channel may be determined based on at least one of bandwidth (BW) or channel index.

[0358] A. Bandwidth (BW): Can indicate the BW of the corresponding channel. Bandwidth information can be indicated in X bits, taking into account the maximum possible number of BWs. For example, bandwidth information can be composed of 1 bit to indicate 320 MHz or 640 MHz. For example, bandwidth information can be composed of 2 bits to indicate 320 MHz, 640 MHz, 1280 MHz, or 2560 MHz.

[0359] B. Channel Index: Can indicate the index of the channel corresponding to the BW. The channel index can be indicated by X bits, taking into account the maximum possible channel index (or the maximum number of possible channels). For example, if there are 8 channels capable of 320 MHz in a 2.16 GHz channel, the channel index can be composed of 3 bits to indicate which of the 8 channels it is a 320 MHz channel. For example, if there is at least one 2.16 GHz channel, it can also indicate which 2.16 GHz channel it is. For example, if there are 4 2.16 GHz channels, the channel index can be composed of 2 bits to indicate which of the 4 channels it is a 2.16 GHz channel. Additionally, or alternatively, it can be indicated by a single channel index without separately indicating which 2.16 GHz or 320 MHz channel it is. For example, if there are 4 2.16 GHz channels and 8 320 MHz channels within a single 2.16 GHz channel, there are a total of 32 channels, and the channel indices can be indicated sequentially using 5 bits. For example, if it is the second 2.16 GHz channel and indicates the first 320 MHz channel within it, assuming the channel index starts from 0, the channel index can be 8.

[0360] Additionally or alternatively, channel information may be indicated by a “channel number” depending on the channelization of the IMMW. For example, channel information may be indicated based on at least one of the following:

[0361] - A channel number (e.g., 1 octet) may refer to the number of a channel that can represent a center frequency. In such cases, the channel number may be indicated together with the aforementioned “A. Bandwidth (BW).”

[0362] Additionally or alternatively, the channel number can represent both the BW and the center frequency.

[0363] - The center frequency may be specified. Additionally or alternatively, the center frequency may be specified together with the aforementioned “A. Bandwidth (BW).”

[0364] Additionally or alternatively, the location of the Primary channel within the corresponding channel can be indicated. For example, using an ordered channel index (e.g., frequency-based ascending order), if the Primary channel is based on 320 MHz and the BW is 640 MHz, the location of the Primary channel can be indicated.

[0365] II. SLS Beamforming Training Information

[0366] The information required when performing BFT in the SLS Phase may include at least one of the following:

[0367] 1) SLS Type: The type of SLS performed by the BFT initiator and the BFT responder.

[0368] For example, an SLS type may include at least one of an initiator Transmit Sector Sweep (initiator Transmit Sector Sweep, I-TXSS), an initiator Receive Sector Sweep (initiator Receive Sector Sweep, I-RXSS), a responder Transmit Sector Sweep (responder Transmit Sector Sweep, R-TXSS), or a responder Receive Sector Sweep (responder Receive Sector Sweep, R-RXSS). X bits may be used for the SLS type to indicate which SLS type is used.

[0369] For example, 4 bits may be used for the SLS type to indicate whether each SLS type is used. As another example, 2 bits may be used for the SLS type to indicate i) whether I-TXSS or I-RXSS is used with 1 bit, and ii) whether R-TXSS or R-RXSS is used with the remaining 1 bit. That is, the SLS type to be performed by the initiator and the SLS type to be performed by the responder can be indicated simultaneously.

[0370] As another example, X bits (e.g., 3 bits) can be used for SLS types, and values ​​such as 1 for only R-TXSS, and 2 for I-TXSS and R-TXSS. In other words, various combinations including the four SLS types mentioned above and / or other SLS types can be indicated.

[0371] 2) Beamforming parameters: These are parameters for performing BFT, such as SLS. For example, based on the beamforming parameters, it can be determined / identified how much TXOP and / or for a specific period BFT can be performed.

[0372] Beamforming parameters may include at least one of the following:

[0373] - Number of Sectors: Total number of sectors to perform BFT (e.g., SLS).

[0374] - Number of TX DMG Antenna: Total number of Transmit DMG Antennas to perform BFT (e.g., SLS)

[0375] - Number of RX DMG Antenna: Total number of Receive DMG Antennaes to perform BFT (e.g., SLS).

[0376] - RXSS Length: The length required to perform RXSS when executing an SLS type. For example, it can specify the total number of receive sectors.

[0377] Additionally or alternatively, each parameter can be indicated based on X bits to indicate the maximum possible number.

[0378] Additionally or alternatively, at least some beamforming parameters (e.g., Number of Sectors, Number of TX DMG Antenna, Number of RX DMG Antenna) may be identified / determined (in advance) based on at least one of Multi-link Probe Request / Response and / or Multi-link setup. In this case, such parameters may not be included.

[0379] III. SLS Identification Information

[0380] The information to be distinguished by ID in the SLS Phase (i.e., SLS identification information) may include at least one of the following:

[0381] 1) Schedule ID: An ID that distinguishes a schedule for at least one SLS Phase. Additionally or alternatively, the schedule ID may be indicated based on X bits to indicate the maximum possible number of schedules.

[0382] Additionally, or alternatively, IDs may overlap between different SLS types. In such cases, schedules can be distinguished based on a 2-tuple of ID and SLS type.

[0383] 2) Initiator ID / Respondent ID: Initiator ID may refer to the AID of a STA that can be a BFT initiator, and Respondent ID may refer to the AID of a STA that can be a BFT responder.

[0384] For example, the AID can be indicated by X bits (i.e., AIDX). This can be the X LSB of the STA's AID.

[0385] For example, the AP's AID can be one of the AIDX values ​​that is not assigned to the STA (e.g., AID12 = 0, 2010).

[0386] For example, the AID may be a Broadcast AID where at least one STA (e.g., all STAs) can be an initiator or responder, rather than the AID of a specific STA. For example, the Broadcast AID may use one of the AIDX values ​​that is not assigned to an STA (e.g., AID12 = 2010, 2044, 2045).

[0387] Additionally or alternatively, to reduce the overhead of the AID field, the Initiator ID field may be omitted through a field indicating when the AP is the initiator. For example, an “AP Initiator field (or trigger field)” may be defined, and if the value of this field is 1, it may be indicated that the AP is the initiator.

[0388] Additionally or alternatively, the Respondent ID field may be omitted through a field indicating that at least one STA (e.g., all STAs) can be a responder. For example, an “All Responder field (or, Destination Broadcast field)” may be defined, and if the value of this field is 1, it may indicate that all STAs can be a responder. Additionally or alternatively, the same meaning may apply to initiators, and an additional separate field (e.g., All Initiator field (or, Source Broadcast field)) may be defined, and if the value of this field is 1, it may indicate that all STAs can be initiators.

[0389] An example of a field / element containing scheduling information according to various embodiments of the present disclosure is illustrated in FIG. 25.

[0390] FIG. 25 shows an example of a field / element containing scheduling information. The format of FIG. 25 is exemplary, and the format of a field / element containing scheduling information is not limited thereto.

[0391] Referring to FIG. 25, a field / element may contain scheduling information (e.g., SLS information). A link ID may indicate which mAP the scheduling information belongs to in the AP MLD. Each field of a field / element may not always be present, and the existence or configuration of each field may vary. For example, a Presence bit for each field may be present to indicate the existence of that field. For example, a Common Info field may contain information regarding whether an SLS type field exists. For example, the information included in the scheduling information may be repeated for each Schedule ID.

[0392] In a field / element containing scheduling information, the Element ID, Length, and / or Element ID Extension fields may be omitted. Additionally, an existing Element ID or a new Element ID may be used for a field / element containing scheduling information.

[0393] Below, an example of beamforming based on scheduling information is described.

[0394] In the present disclosure, the BF frame / PPDU is a frame transmitted to perform beamforming training (BT), and the BF Feedback (fb) / PPDU can be considered as a frame / PPDU that transmits BT result information obtained through the BF frame / PPDU. The BF frame / PPDU and the BF fb frame / PPDU may be BF frame / PPDUs used in existing DMGs or new frame / PPDUs, but are not limited thereto. Additionally, the BF frame / PPDU and the BF fb frame / PPDU may contain information for performing beamforming. In the following description, the BF frame and the BF fb frame may be replaced by the BF PPDU and the BF fb PPDU. The Schedule ID and SLS channel may be omitted for convenience of explanation, but may be assigned for each Schedule.

[0395] Figure 26 shows an example of I-TXSS in the SLS Phase.

[0396] Referring to FIG. 26, the sAP can transmit scheduling information via the Beacon (B), along with information about a specific interval in the BSS of mAP 1, and via the AID12 field, instruct mAP 1 (AID = 0) as the initiator and all STAs (AID = 2045 (Broadcast AID) as the responders to operate for I-TXSS in that interval. Additionally or alternatively, the Beacon (B) may be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field may be replaced with AID11, AID7, etc. Additionally or alternatively, the initiator ID may not be included via the AP Initiator field (enable = 1). Additionally or alternatively, the responder ID may not be included via the AP Responder field (enable = 1).

[0397] Therefore, mAP 1 can transmit BF frames in a broadcast format. Additionally, or alternatively, mAP 1 may transmit BF frames to specific STAs. The number of transmitted BF frames can be the total number of sectors considering the number of DMG antennas of mAP 1, but is not limited thereto. mSTAs can select / determine the optimal DMG antenna and / or sector while receiving BF frames transmitted by mAP 1.

[0398] Additionally, the ST, Duration, Interval, and / or SLS channel of the SLS Time may also be specified. The number of sectors and / or antennas may be negotiated in advance; in this case, the corresponding field may not exist or may be reserved. Similarly, since the RXSS length does not perform RXSS, this field may not exist or may be reserved.

[0399] mAP 1 can transmit BF frames based on at least one channel access method. For example, mAP 1 can perform back-off via EDCA or determine whether to transmit a frame via CCA during the PIFS interval based on the Start time (e.g., transmit frame if IDLE).

[0400] The interval between BF frames transmitted from the same DMG antenna can be SBIFS or SIFS (or PIFS). The interval between BF frames transmitted from different DMG antennas can be LBIFS or PIFS (or SIFS).

[0401] Figure 27 shows examples of I-TXSS and R-TXSS in the SLS Phase.

[0402] Referring to FIG. 27, the sAP can transmit scheduling information via the Beacon (B), along with information about a specific interval in the BSS of mAP 1, and via the AID12 field, instruct mAP 1 (AID = 0) as the initiator and all STAs (AID = 2045 (Broadcast AID) as the responders to operate for I-TXSS and R-TXSS in that interval. Additionally or alternatively, the Beacon (B) may be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field may be replaced with AID11, AID7, etc. Additionally or alternatively, the initiator ID may not be included via the AP Initiator field (enable = 1). Additionally or alternatively, the responder ID may not be included via the AP Responder field (enable = 1).

[0403] Therefore, mAP 1 can transmit BF frames in a broadcast format. Additionally, or alternatively, mAP 1 may transmit BF frames to specific STAs. The number of transmitted BF frames can be the total number of sectors considering the number of DMG antennas of mAP 1, but is not limited thereto. mSTAs can select / determine the optimal DMG antenna and / or sector while receiving BF frames transmitted by mAP 1.

[0404] mSTA 1 and mSTA 2 may each transmit BF frames to mAP 1 for R-TXSS when occupying a channel. Similarly, the number of BF frames transmitted may be, but is not limited to, the total number of sectors considering the number of DMG antennas for each mSTA. While transmitting BF frames, mSTA 1 and mSTA 2 may each include optimal DMG antenna and / or sector information selected / determined during mAP 1's I-TXSS in the BF frames.

[0405] mAP 1 can select / determine the optimal DMG antenna and / or sector while receiving BF frames transmitted by each mSTA. The selected / determined optimal DMG antenna and / or sector can be transmitted to each mSTA via BF fb frames.

[0406] Additionally, the ST, Duration, Interval, and / or SLS channel of the SLS Time may also be specified. The number of sectors and / or antennas may be negotiated in advance; in this case, the corresponding field may not exist or may be reserved. Similarly, since the RXSS length does not perform RXSS, this field may not exist or may be reserved.

[0407] mAP 1, mSTA 1 and / or mSTA 2 may transmit BF frames based on at least one channel access method. For example, mAP 1, mSTA 1 and / or mSTA 2 may perform back-off via EDCA or determine whether to transmit frames via CCA during the PIFS interval based on the Start time (e.g., transmit frames if IDLE). Additionally or alternatively, if I-TXSS and R-TXSS are performed in the SLS Phase, I-TXSS may proceed first.

[0408] The interval between BF frames transmitted from the same DMG antenna can be SBIFS or SIFS (or PIFS). The interval between BF frames transmitted from different DMG antennas can be LBIFS or PIFS (or SIFS).

[0409] Figure 28 shows an example of I-RXSS in the SLS Phase.

[0410] Referring to FIG. 28, the sAP can transmit scheduling information via the Beacon (B), along with information about a specific interval in the BSS of mAP 1, and via the AID12 field, instruct mAP 1 (AID = 0) as the initiator and mSTA 2 (AID = 200) as the responder to operate for I-RXSS in that interval. Additionally or alternatively, the Beacon (B) may be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field may be replaced with AID11, AID7, etc. Additionally or alternatively, the initiator ID may not be included via the AP Initiator field (enable = 1).

[0411] Therefore, mAP 1 can transmit BF frames to mSTA 2. The number of BF frames transmitted may be determined based on the RXSS Length, but is not limited thereto. At least one (e.g., all) BF frames of mAP 1 may be transmitted through the same DMG antenna and / or sector. Additionally or alternatively, the same DMG antenna and / or sector may be the optimal value obtained through feedback information by performing I-TXSS on the same initiator and responder previously.

[0412] mSTA 2 may sequentially change the DMG antenna and / or sector by up to RXSS Length to receive each BF frame from mAP 1 in order to find the optimal RX sector. If R-TXSS was performed prior to I-RXSS for the same initiator and responder, mAP 1 may include the optimal DMG antenna and / or sector information for mSTA 2's TX in the BF frame.

[0413] Additionally, the ST, Duration, Interval, and / or SLS channel of the SLS Time may also be specified. The number of sectors and / or antennas may be negotiated in advance, in which case the corresponding fields may not exist or may be reserved.

[0414] Here, mAP 1 can transmit a BF frame based on at least one channel access method. For example, mAP 1 can perform back-off via EDCA or determine whether to transmit a frame via CCA during the PIFS interval based on the Start time (e.g., transmit frame if IDLE).

[0415] The interval between BF frames transmitted from the same DMG antenna can be SBIFS or SIFS (or PIFS). The interval between BF frames transmitted from different DMG antennas can be LBIFS or PIFS (or SIFS).

[0416] Figure 29 shows an example of I-TXSS & R-RXSS in the SLS Phase.

[0417] Referring to FIG. 29, the sAP can transmit scheduling information via the Beacon (B), along with information about a specific interval in the BSS of mAP 1, and via the AID12 field, instruct mAP 1 (AID = 0) as the initiator and mSTA 1 (AID = 100) as the responder to operate for I-TXSS and R-RXSS in that interval. Additionally or alternatively, the Beacon (B) may be replaced with another announcement frame (or management frame). Additionally or alternatively, the AID12 field may be replaced with AID11, AID7, etc. Additionally or alternatively, the initiator ID may not be included via the AP Initiator field (enable = 1).

[0418] Therefore, mAP 1 can transmit BF frames to mSTA 1 for I-TXSS. The number of BF frames transmitted can be the number of all sectors considering the number of DMG antennas of mAP 1, but is not limited thereto. mSTA 1 can select / determine the optimal DMG antenna and / or sector while receiving the BF frames transmitted by mAP 1.

[0419] mSTA 1 may transmit BF frames for R-RXSS. The number of BF frames transmitted may be determined based on the RXSS Length, but is not limited thereto. Additionally, at least one (e.g., all) BF frames of mSTA 1 may be transmitted through the same DMG antenna and / or sector. Additionally, or alternatively, the same DMG antenna and / or sector may be the optimal value obtained through feedback information by performing R-TXSS on the same initiator and responder previously.

[0420] mAP 1 may sequentially change the DMG antenna and / or sector by up to RXSS Length to receive each BF frame from mSTA 2 in order to find the optimal RX sector. mSTA 1 may include the optimal DMG antenna and / or sector information for mAP 1's TX in the BF frame.

[0421] Additionally, the ST, Duration, Interval, and / or SLS channel of the SLS Time may also be specified. The number of sectors and / or antennas may be negotiated in advance, in which case the corresponding fields may not exist or may be reserved.

[0422] Here, mAP 1 and / or mSTA 1 may transmit BF frames based on at least one channel access method. For example, mAP 1 and / or mSTA 1 may perform back-off via EDCA or determine whether to transmit frames via CCA during the PIFS interval based on the Start time (e.g., transmit frames if IDLE). Additionally, or alternatively, if I-TXSS and R-RXSS are performed in the SLS Phase, I-TXSS may proceed first.

[0423] The interval between BF frames transmitted from the same DMG antenna can be SBIFS or SIFS (or PIFS). The interval between BF frames transmitted from different DMG antennas can be LBIFS or PIFS (or SIFS).

[0424] 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.

[0425] For example, the processor (121) and / or processing chip (124) of FIG. 1 may be configured to perform operations performed in the AP MLD of the present disclosure by executing instructions stored in memory (122). The operations include: an operation in which a first AP associated with the AP MLD and associated with a first frequency band transmits information about one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; an operation in which the first AP receives one or more request frames to request an association between the second AP and one or more STAs (stations) among the one or more other APs, wherein each of the one or more STAs is associated with a corresponding non-AP MLD and associated with the second frequency band; and an operation in which the first AP transmits one or more response frames for the one or more request frames. The method includes an operation in which the first AP transmits scheduling information to the second AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and the one or more STAs connected to the second AP.

[0426] 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 a non-AP MLD in the present disclosure by executing instructions stored in memory (112, 520). The operations include: an operation in which a first STA (station) associated with the non-AP MLD and associated with a first frequency band receives information from a first AP associated with the AP MLD and associated with the first frequency band regarding one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; an operation in which the first STA transmits a request frame to request a connection between the second AP among the one or more other APs and the second STA associated with the non-AP MLD and associated with the second frequency band; and an operation in which the first STA receives a response frame for the request frame. The method includes an operation in which the first STA receives scheduling information for the second AP from the first AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and one or more STAs connected to the second AP.

[0427] 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.

[0428] 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 MLD in this disclosure, based on execution by a processor (e.g., the processor (121) and / or processing chip (124) of FIG. 1). The operations include: an operation in which a first AP associated with the AP MLD and associated with a first frequency band transmits information about one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; an operation in which the first AP receives one or more request frames to request an association between the second AP and one or more STAs among the one or more other APs, wherein each of the one or more STAs is associated with a corresponding non-AP MLD and associated with the second frequency band; and an operation in which the first AP transmits one or more response frames for the one or more request frames. The method includes an operation in which the first AP transmits scheduling information to the second AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and the one or more STAs connected to the second AP.

[0429] 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 a non-AP MLD 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: an operation in which a first STA (station) associated with the non-AP MLD and associated with a first frequency band receives information from a first AP associated with the AP MLD and associated with the first frequency band regarding one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band; an operation in which the first STA transmits a request frame to request a connection between the second AP among the one or more other APs and the second STA associated with the non-AP MLD and associated with the second frequency band; The operation of the first STA receiving a response frame for the request frame; and the operation of the first STA receiving scheduling information for the second AP from the first AP, wherein the scheduling information includes at least one of i) identification information for an initiator who initiates frame exchange among the STAs associated with the second AP, ii) identification information for at least one responder who performs frame exchange with the initiator among the STAs associated with the second AP, or iii) information for a time period for frame exchange, and the STAs associated with the second AP include the second AP and one or more STAs connected to the second AP.

[0430] 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).

[0431] 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.

[0432] 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.

[0433] 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.

[0434] 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.

[0435] 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.

[0436] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0437] 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.

[0438] 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.

[0439] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0440] 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.

[0441] 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.

[0442] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0443] 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.

[0444] 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.

[0445] 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.

[0446] The present disclosure may have various advantageous effects.

[0447] For example, an STA connected to an MLD and operating in the sub-7GHz band can be scheduled to perform frame switching with an STA connected to the same MLD and operating in the mmWave band. By performing such schedule-based frame switching, unnecessary power consumption can be reduced.

[0448] 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.

[0449] 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. In a method performed by an AP (access point) MLD (multi-link device), A step in which a first AP associated with a first frequency band and affiliated with the above AP MLD transmits information about one or more other APs associated with the above AP MLD and associated with a second frequency band higher than the first frequency band; The step of the first AP receiving one or more request frames to request an association between the second AP and one or more STAs (stations) among the one or more other APs, Each of the above one or more STAs is associated with a corresponding non-AP MLD and is associated with the second frequency band; The step of the first AP transmitting one or more response frames for the one or more request frames; and The above first AP includes the step of transmitting scheduling information to the above second AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. A method comprising STAs associated with the second AP, the second AP and one or more STAs connected to the second AP.

2. A method according to claim 1, wherein the identification information for the initiator comprises at least one of the identifier (ID) of the initiator, information indicating whether the second AP is an initiator, or information indicating whether any STA among the STAs associated with the second AP can be an initiator.

3. A method according to claim 2, wherein the identifier of the initiator is set to a value representing the STA that is the initiator among the STAs associated with the second AP, or a value representing that any STA among the STAs associated with the second AP can be the initiator.

4. A method of claim 2 in which the identifier of the initiator is omitted based on the fact that the identification information for the initiator includes information indicating that the second AP is the initiator.

5. A method of claim 2 in which the identifier of the initiator is omitted, based on the fact that the identification information for the initiator includes information indicating that any STA among the STAs associated with the second AP may be the initiator.

6. A method according to claim 1, wherein the identification information for at least one respondent comprises at least one of the respondent's identifier or information indicating whether all STAs connected to the initiator among the STAs associated with the second AP are respondents.

7. A method according to claim 6, wherein the identifier of the respondent is set to a value indicating a respondent STA among the STAs associated with the second AP, or a value indicating that all STAs connected to the initiator among the STAs associated with the second AP are respondents.

8. A method of claim 6 in which the identifier of the respondent is omitted, based on the fact that the identification information for at least one respondent includes information indicating that all STAs connected to the initiator among the STAs associated with the second AP are respondents.

9. A method according to claim 1, wherein the information regarding the time interval comprises at least one of information regarding the start time of the time interval, information regarding the length of the time interval, or information regarding the interval between consecutive time intervals.

10. A method according to claim 1, wherein the scheduling information further includes information regarding the frequency / channel for the frame exchange.

11. A method according to claim 10, wherein the information regarding the frequency / channel comprises at least one of information regarding the bandwidth for the frame exchange or an index of the channel associated with the bandwidth.

12. A method according to claim 1, wherein the frame exchange includes data frame exchange.

13. In claim 1, the frame exchange includes frame exchange for beamforming training (BFT), and The above time interval is a method that includes the duration of the SLS (sector level sweep) phase.

14. In claim 13, the scheduling information further comprises at least one of information regarding the SLS type, information regarding beamforming parameters, information regarding the number of sectors for BFT / SLS, information regarding the number of transmitting antennas for BFT / SLS, information regarding the number of receiving antennas for BFT / SLS, information regarding the RXSS (Receive Sector Sweep) length, or an identifier (ID) of the corresponding SLS step. The above SLS type is a method comprising at least one of an initiator TXSS (initiator Transmit Sector Sweep, I-TXSS), an initiator RXSS (initiator Receive Sector Sweep, I-RXSS), a responder TXSS (responder TXSS, R-TXSS), or a responder RXSS (responder RXSS, R-RXSS).

15. In claim 1, the first frequency band is a sub-7 GHz band, and The above second frequency band is a millimeter wave (mmWave) band.

16. In an AP (access point) MLD (multi-link device), 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 in which a first AP associated with a first frequency band and affiliated with the above AP MLD transmits information about one or more other APs associated with the above AP MLD and associated with a second frequency band higher than the first frequency band; The operation of the first AP receiving one or more request frames to request an association between the second AP and one or more STAs (stations) among the one or more other APs, Each of the above one or more STAs is associated with a corresponding non-AP MLD and is associated with the second frequency band; The operation of the first AP transmitting one or more response frames for the one or more request frames; and The above first AP includes an operation of transmitting scheduling information to the above second AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. The STAs associated with the second AP are an AP MLD comprising the second AP and the one or more STAs connected to the second AP.

17. In the device, At least one processor; and It includes at least one memory functionally coupled with the above-mentioned at least one processor, and The above at least one memory stores instructions for performing operations based on execution by the above at least one processor, and the operations are: An operation in which a first AP (access point) associated with a first frequency band and affiliated with an MLD (multi-link device) transmits information about one or more other APs associated with a second frequency band higher than the first frequency band and affiliated with the said AP MLD; The operation of the first AP receiving one or more request frames to request an association between the second AP and one or more STAs (stations) among the one or more other APs, Each of the above one or more STAs is associated with a corresponding non-AP MLD and is associated with the second frequency band; The operation of the first AP transmitting one or more response frames for the one or more request frames; and The above first AP includes an operation of transmitting scheduling information to the above second AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. A device comprising the STAs associated with the second AP, the second AP, and the one or more STAs connected to the second AP.

18. In a non-transitory computer-readable medium (CRM) storing program code that implements instructions for performing operations based on execution by at least one processor, said operations are: An operation in which a first AP (access point) associated with a first frequency band and affiliated with an MLD (multi-link device) transmits information about one or more other APs associated with a second frequency band higher than the first frequency band and affiliated with the said AP MLD; The operation of the first AP receiving one or more request frames to request an association between the second AP and one or more STAs (stations) among the one or more other APs, Each of the above one or more STAs is associated with a corresponding non-AP MLD and is associated with the second frequency band; The operation of the first AP transmitting one or more response frames for the one or more request frames; and The above first AP includes an operation of transmitting scheduling information to the above second AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. The STAs associated with the second AP are a CRM comprising the second AP and one or more STAs connected to the second AP.

19. A method performed by a non-AP (access point) MLD (multi-link device), A first STA (station) associated with the non-AP MLD and associated with a first frequency band receives information about one or more other APs associated with the AP MLD and associated with a second frequency band higher than the first frequency band from a first AP associated with the AP MLD and associated with the first frequency band; The step of the first STA transmitting a request frame to request a connection between the second STA associated with the second frequency band and the second AP among the one or more other APs and the non-AP MLD; The step of the first STA receiving a response frame for the request frame; and The above-mentioned first STA includes the step of receiving scheduling information for the second AP from the first AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. A method comprising STAs associated with the second AP, the second AP and one or more STAs connected to the second AP.

20. In a non-AP (access point) MLD (multi-link device), 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 in which a first STA (station) associated with the above-mentioned non-AP MLD and associated with a first frequency band receives information about one or more other APs associated with the above-mentioned AP MLD and associated with a second frequency band higher than the first frequency band from a first AP associated with the above-mentioned AP MLD and associated with the above-mentioned AP MLD; The operation of the first STA transmitting a request frame to request a connection between the second STA associated with the second frequency band and the second AP among the one or more other APs and the non-AP MLD; The operation of the first STA receiving a response frame for the request frame; and The above first STA includes an operation of receiving scheduling information for the second AP from the first AP, and The above scheduling information includes at least one of i) identification information for an initiator among the STAs associated with the second AP that initiates frame exchange, ii) identification information for at least one responder among the STAs associated with the second AP that performs frame exchange with the initiator, or iii) information for a time period for frame exchange. The STAs associated with the second AP are a non-AP MLD comprising the second AP and one or more STAs connected to the second AP.

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