WO2025165131A1 - Dynamic power saving in downlink multi-user transmission in wireless lan system - Google Patents

Abstract

The present disclosure relates to dynamic power saving in downlink multi-user transmission in a wireless LAN system. According to an embodiment of the present disclosure, a method performed by an AP configured to operate in a wireless LAN system comprises the steps of: entering a listening state of a dynamic power save (PS) mode; in the listening state, detecting downlink data to be transmitted to one or more stations (STAs); on the basis of detection of the downlink data to be transmitted, transmitting an initial control frame (ICF) to the one or more STAs, wherein the ICF is for initiating downlink transmission in the dynamic PS mode; and after transmitting the ICF, transmitting the downlink data to the one or more STAs in the frame exchange state of the dynamic PS mode.

Description

Dynamic power savings in downlink multi-user transmission in wireless LAN systems.

The present disclosure relates to dynamic power saving in downlink multi-user transmission in a wireless LAN system.

Next-generation Wi-Fi (e.g., IEEE 802.11be and/or later) aims to support ultra-high reliability when transmitting signals to STAs. To achieve this, various technologies are being considered to support high throughput, low latency, and extended range. For example, while APs can be powered all the time, in network environments with multiple APs, power consumption by APs can be significant, necessitating power savings.

The present disclosure provides a method and device for dynamic power saving in downlink multi-user transmission in a wireless LAN system.

According to an embodiment of the present disclosure, a method performed by an AP configured to operate in a wireless LAN system includes: entering a listening state of a dynamic power save (PS) mode; detecting, in the listening state, downlink data to be transmitted to one or more STAs; transmitting, based on the detection of the downlink data to be transmitted, an initial control frame (ICF) for initiating downlink transmission in the dynamic PS mode to the one or more STAs; and transmitting, after transmitting the ICF, the downlink data to the one or more STAs in a frame exchange state of the dynamic PS mode.

According to an embodiment of the present disclosure, a method performed by an STA configured to operate in a wireless LAN system comprises the steps of: receiving an initial control frame (ICF) for initiating downlink transmission in an access point (AP) flexible PS mode; and receiving downlink data from the AP after receiving the ICF, wherein the ICF is transmitted from the AP based on the AP detecting the downlink data to be transmitted to the STA in a listening state of the flexible PS mode, and the downlink data is transmitted from the AP while the AP is in a frame exchange state of the flexible PS mode.

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

The present disclosure may have various advantageous effects.

For example, when AP and non-AP STAs operate as dynamic PS, AP/STA can operate in a listening state with limited capabilities/configurations other than the period in which frame exchange is performed, thereby reducing unnecessary power consumption.

For example, if an AP operates as a dynamic PS and at least one non-AP STA has a different power management mode, the AP or some STAs can reduce power consumption in a listening state, and some non-AP STAs in a doze state can achieve greater power savings.

The beneficial effects that can be achieved through specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, various technical effects may be understood and/or derived from the present disclosure by those skilled in the art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure.

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

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

Figure 3 is a diagram illustrating a general link setup process.

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

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

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

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

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

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

Figure 10 shows the operation according to UL-MU.

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

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

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

Figure 14 shows the trigger frame format.

Figure 15 shows an example of a random backoff procedure.

Figure 16 illustrates an example of a procedure related to NAV setting.

Figure 17 shows an example of per-link power saving operation.

FIG. 18 illustrates an example of a power management operation according to an embodiment of the present disclosure.

Figure 19 shows an example of EMLSR operation.

FIG. 20 illustrates an example of a method performed by an AP for dynamic power saving according to an embodiment of the present disclosure.

FIG. 21 illustrates an example of signal flow between an AP and a STA for dynamic power saving according to an embodiment of the present disclosure.

FIG. 22 illustrates an example of an ICF format for DL MU transmission in a fluid PS operation according to an embodiment of the present disclosure.

FIG. 23 illustrates an example of a response frame format for ICF in a fluid PS operation according to an embodiment of the present disclosure.

FIG. 24 illustrates a first example of a frame sequence for DL MU transmission in a fluid PS operation according to an embodiment of the present disclosure.

FIG. 25 illustrates a second example of a frame sequence for DL MU transmission in a fluid PS operation according to an embodiment of the present disclosure.

In this disclosure, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this disclosure can be interpreted as “A and/or B.” For example, “A, B or C” in this disclosure can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

As used herein, a slash (/) or a comma can mean "and/or." For example, "A/B" can mean "A and/or B." Accordingly, "A/B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

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

In addition, parentheses used in the present disclosure may mean “for example.” Specifically, when “control information (UHR-Signal field)” is indicated, the “UHR-Signal field” may be suggested as an example of “control information.” In other words, the “control information” of the present disclosure is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be suggested as an example of “control information.” In addition, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be suggested as an example of “control information.”

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

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

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

The following examples of the present disclosure can be applied to various wireless communication systems. For example, the following examples of the present disclosure can be applied to a wireless local area network (WLAN) system. For example, the present disclosure can be applied to the IEEE 802.11a/g/n/ac/ax/be/bn standards. Furthermore, the examples of the present disclosure can be applied to the Ultra High Reliability (UHR) standard or a next-generation wireless LAN standard that enhances IEEE 802.11bn. Furthermore, the examples of the present disclosure can be applied to a mobile communication system. For example, the examples of the present disclosure can be applied to a mobile communication system based on the Long Term Evolution (LTE) standard and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.

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

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

An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of the present disclosure may also be referred to by various names such as a mobile terminal, a wireless device, a Wireless Transmit/Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a Mobile Subscriber Unit, or simply a user. The STA (110, 120) of the present disclosure may also be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, etc. The STA (110, 120) of the present disclosure may also be referred to by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, etc.

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

The STA (110, 120) of the present disclosure can support various communication standards other than the IEEE 802.11 standard. For example, it can support communication standards according to the 3GPP standard (e.g., LTE, LTE-A, 5G NR standard). In addition, the STA of the present disclosure can be implemented in various devices such as a mobile phone, a vehicle, a personal computer, etc. In addition, the STA of the present disclosure can support communication for various communication services such as voice calls, video calls, data communications, and autonomous driving (Self-Driving, Autonomous-Driving).

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

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

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

The transceiver (113) of the first STA performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.).

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

For example, the second STA (120) can perform the intended operation of a non-AP STA. For example, the transceiver (123) of the non-AP performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.).

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

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

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

In the following specification, devices called (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting/receiving) device, (transmitting/receiving) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, devices indicated as (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting/receiving) device, (transmitting/receiving) apparatus, network, etc. without specific drawing symbols may also refer to the STA (110, 120) of FIG. 1. For example, in the example below, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. In addition, in the example below, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processor (111, 121) of FIG. 1. For example, an example of an operation for generating a transmission/reception signal or performing data processing or operation in advance for a transmission/reception signal may include 1) an operation for determining/obtaining/configuring/computing/decoding/encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation for determining/configuring/obtaining time resources or frequency resources (e.g., subcarrier resources) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 3) an operation for determining/configuring/obtaining a specific sequence (e.g., a pilot sequence, an STF/LTF sequence, an extra sequence applied to SIG) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 4) a power control operation and/or a power saving operation applied to an STA, 5) an operation related to determining/obtaining/configuring/computing/decoding/encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields/subfields/control fields/parameters/power, etc.) used by various STAs for determining/acquiring/configuring/computing/decoding/encoding transmission/reception signals can be stored in the memory (112, 122) of FIG. 1.

The device/STA of the sub-drawing (a) of FIG. 1 described above can be modified as in the sub-drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of the present disclosure will be described based on the sub-drawing (b) of FIG. 1.

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

The mobile terminal, wireless device, Wireless Transmit/Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, user STA, network, Base Station, Node-B, Access Point (AP), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and/or transmitting Apparatus described below may refer to the STA (110, 120) illustrated in the sub-drawings (a)/(b) of FIG. 1, or may refer to the processing chip (114, 124) illustrated in the sub-drawing (b) of FIG. 1. That is, the technical feature of the present disclosure may be performed in the STA (110, 120) illustrated in the sub-drawings (a)/(b) of FIG. 1, or may be performed only in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1. For example, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal generated in the processor (111, 121) illustrated in the sub-drawings (a)/(b) of FIG. 1 is transmitted through the transceiver (113, 123) illustrated in the sub-drawings (a)/(b) of FIG. 1. Alternatively, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal to be transmitted to the transceiver (113, 123) is generated in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1.

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

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

The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and/or a data processing device. The processor may be an application processor (AP). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or an enhanced processor thereof.

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

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

The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

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

A BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.

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

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

In a BSS such as the upper part of Fig. 2, a network between APs (225, 230) and a network between APs (225, 230) and STAs (200-1, 205-1, 205-2) can be implemented. However, it may also be possible to establish a network and perform communication between STAs without an AP (225, 230). A network that establishes a network and performs communication between STAs without an AP (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

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

Referring to the bottom of Fig. 2, the IBSS is a BSS that operates in ad-hoc mode. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, the STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In the IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and access to the distributed system is not permitted, forming a self-contained network.

Figure 3 is a diagram illustrating a general link setup process.

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

Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In a BSS, the AP transmits the beacon frame, so the AP becomes the responder. In an IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests/responses on channel 2) in the same manner.

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

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

The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group.

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

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

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

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

As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate over a remote link. The MLDs can be categorized into AP MLDs including multiple AP STAs and non-AP MLDs including multiple non-AP STAs. That is, the AP MLD can include affiliated APs (i.e., AP STAs), and the non-AP MLD can include affiliated STAs (i.e., non-AP STAs, or user-STAs).

A multilink may include a first link and a second link, and different channels/subchannels/frequency resources may be allocated to the first and second links. The first and second multilinks may be identified through a link ID of 4 bits (or other n bits). The first and second links may be configured in the same 2.4 GHz, 5 GHz, or 6 GHz band. Alternatively, the first link and the second link may be configured in different bands.

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

In the example of FIG. 4, AP1 may initiate a multi-link setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 may transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1/2/3) illustrated in FIG. 4 may be identical to the AP illustrated in FIG. 1 and/or FIG. 2, and each non-AP (e.g., non-AP1/2/3) illustrated in FIG. 4 may be identical to the STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and/or FIG. 2.

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

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

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

The processor (510) of FIG. 5 may be identical to the processor (111, 121) of FIG. 1. Alternatively, the processor (510) of FIG. 5 may be identical to the processing chip (114, 124) of FIG. 1.

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.

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

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

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

The STA (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) of the present disclosure can transmit and/or receive the PPDU of FIG. 6. The PPDU described in the present disclosure may have, for example, the structure of FIG. 6. In addition, the PPDU described in the present disclosure may be called by various names such as a transmission PPDU, a reception PPDU, a first type PPDU, or an Nth type PPDU, etc. The PPDU described in the present disclosure can be used in a WLAN system defined according to IEEE 802.11bn and/or a next-generation WLAN system that improves upon IEEE 802.11bn.

The PPDU of FIG. 6 may be related to various PPDU types used in a UHR system. For example, the example of FIG. 6 may be used for at least one of a single-user (SU) mode/type/transmission, a multi-user (MU) mode/type/transmission, and a null data packet (NDP) mode/type/transmission related to channel sounding. For example, if the example of FIG. 6 is related to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 6 is used for a trigger-based (TB) mode, the UHR-SIG of FIG. 6 may be omitted. In other words, an STA that has received a trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU with the UHR-SIG omitted in the example of FIG. 6.

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

Each block illustrated in Fig. 6 may be called a field/subfield/signal, etc. The names of these fields/subfields/signals may be, as illustrated in Fig. 6, L-STF (legacy short training field), L-LTF (legacy long training field), L-SIG (legacy signal), RL-SIG (repeated L-SIG), U-SIG (Universal Signal), UHR-SIG (UHR-signal), etc.

The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in FIG. 6 may be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields may be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields may be expressed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields may be expressed in units of 78.125 kHz.

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

The L-SIG field of FIG. 6 may include, for example, 24 bits of bit information. For example, the 24 bits of information may include a 4 bit Rate field, a 1 bit Reserved bit, a 12 bit Length field, a 1 bit Parity bit, and a 6 bit Tail bit. For example, the 12 bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12 bit Length field may be determined based on the type of the PPDU. For example, if the PPDU is a non-HT (non-High Throughput), HT (High Throughput), VHT (Very High Throughput) PPDU, or an EHT (extremely high throughput) PPDU or UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is a HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, for non-HT, HT, VHT PPDU, EHT PPDU, UHR PPDU, the value of the Length field can be determined as a multiple of 3, and for HE (High-Efficiency) PPDU, the value of the Length field can be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, the Length field in an UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

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

For example, (non-AP and AP) STA can generate RL-SIG, which is generated in the same manner as L-SIG. BPSK modulation can be applied to RL-SIG. Receiving (non-AP and AP) STA can determine whether the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of RL-SIG. In other words, if RL-SIG is present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of HE PPDU, EHT PPDU, or UHR PPDU. In other words, if RL-SIG is not present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of non-HT PPDU, HT PPDU, or VHT PPDU. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

After the RL-SIG in Fig. 6, a U-SIG (Universal SIG) may be inserted. The U-SIG may be called by various names such as the first SIG field, the first SIG, the first type SIG, the control signal, the control signal field, the first (type) control signal, the common control field, and the common control signal.

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

For example, A bit information (e.g., 52 uncoded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 uncoded bits) out of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bits of information (e.g., 26 uncoded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA can perform convolutional encoding (i.e., BCC encoding) based on a rate of R=1/2 to generate 52 coded bits, and perform interleaving on the 52 coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols allocated to each U-SIG symbol. A single U-SIG symbol can be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA can be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21.

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

The A bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits can be fixed or variable. For example, the version-independent bits can be assigned only to the first symbol of the U-SIG, or the version-independent bits can be assigned to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

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

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

For example, the version-independent bits of U-SIG may include a 1-bit UL/DL flag field. The first value of the 1-bit UL/DL flag field relates to UL communication, and the second value of the UL/DL flag field relates to DL communication.

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

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

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

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

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

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.

For example, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding the preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

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

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

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

UHR-SIG provides additional signals to the U-SIG field to enable STAs to interpret/decode UHR PPDUs. The UHR-SIG field may contain U-SIG overflow bits that are common to all users. The UHR-SIG field also contains resource allocation information, allowing STAs to look up resources used in fields containing data fields/UHR-STF/UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 6 can be determined based on RUs (resource units) defined by multiple subcarriers/tones. That is, the UHR-LTF, UHR-STF, and data fields of the present disclosure can be transmitted/received through RUs (resource units) defined by multiple subcarriers/tones.

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

As shown at the top of Fig. 7, 26 units (i.e., units corresponding to 26 tones) can be arranged. Six tones can be used as a guard band in the leftmost band of the 20 MHz band, and five tones can be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones can be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones can exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be allocated for a receiving station, i.e., a user.

Meanwhile, the RU arrangement of FIG. 7 is utilized not only in a situation for multiple users (MUs) but also in a situation for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of FIG. 4, in which case three DC tones can be inserted.

In the example of Fig. 7, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are proposed. Since the specific sizes of these RUs can be expanded or increased, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones). In the present disclosure, N-RU may be represented as N-tone RU, etc. For example, 26-RU may be represented as 26-tone RU.

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

As in the example of Fig. 7 where RUs of various sizes were used, the example of Fig. 8 can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, 5 DC tones can be inserted at the center frequency, 12 tones can be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones can be used as a guard band in the rightmost band of the 40 MHz band.

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

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

Figure 10 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can acquire a TXOP (1025) by performing channel access through contending (i.e., backoff operation) and transmit a trigger frame (1030). That is, the transmitting STA (e.g., AP) can transmit a PPDU including a trigger frame (1030). When a PPDU including a trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

TB PPDUs (1041, 1042) are transmitted at the same time and can be transmitted from multiple STAs (e.g., User STAs) whose AIDs are indicated in the Trigger frame (1030). The ACK frame (1050) for the TB PPDU can be implemented in various forms. For example, the ACK frame (1050) for the TB PPDU can be implemented in the form of a BA (block ACK).

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

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

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

The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz within the 2.4 GHz band may have multiple channel indices (e.g., indices 1 through 14). For example, the center frequency of a 20 MHz channel assigned channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned channel index N may be (2.407 + 0.005*N) GHz. The channel indices may be referred to by various names, such as channel numbers. The specific numerical values of the channel indices and center frequencies may change.

Figure 11 exemplarily illustrates four channels within the 2.4 GHz band. The illustrated first frequency region (1110) to fourth frequency region (1140) may each include one channel. For example, the first frequency region (1110) may include channel 1 (a 20 MHz channel having an index of 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency region (1120) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency region (1130) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency region (1140) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

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

The 5 GHz band may be referred to by other names, such as a second band/band, etc. The 5 GHz band may refer to a frequency range in which channels with center frequencies greater than or equal to 5 GHz and less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include multiple channels between 4.5 GHz and 5.5 GHz. The specific figures shown in FIG. 12 are subject to change.

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

Within the 5 GHz band, multiple channels can be configured, and the bandwidth of each channel can be variously configured, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency domain/range within UNII-1 and UNII-2 can be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain/range can be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain/range can be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain/range can be divided into one channel through a 160 MHz frequency domain.

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

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

For example, the 20 MHz channel of FIG. 13 can be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 13 can have an index of 1 (or channel index, channel number, etc.), and a center frequency of 5.945 GHz can be assigned. That is, the center frequency of the indexed channel N can be determined as (5.940 + 0.005*N) GHz.

Accordingly, the indexes (or channel numbers) of the 20 MHz channels of FIG. 13 are 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, It can be 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule mentioned above, the indices of the 40 MHz channels in Fig. 13 can be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

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

For example, the management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames/signals defined in conventional WLAN. For the management frame, the values of the type fields (B3 and B2) of the MAC header are set to 00. In addition, the values of the subtype fields (B7, B6, B5, B4) of the MAC header are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

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

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

The type of the MAC frame used in the present disclosure can be identified through the type field/information and the subtype field/information included in the frame control field of the header of the MAC frame (i.e., the MAC header). For example, the “trigger frame” of the present disclosure can mean a MAC frame in which the type bits B3 and B2 bits in the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 bits in the frame control field are also set to 0010. Various MAC frames described in the present disclosure are inserted/included in the data field of various PPDUs (e.g., HE/VHT/HE/EHT/UHR PPDUs).

Figure 14 illustrates a trigger frame format. The trigger frame format may also be referred to as the structure of a trigger frame.

Referring to FIG. 14, a trigger frame may include a frame control field, a duration/ID field, a receiver address (RA) field, a transmitter address (TA) field, a common info field, a user info list field, a padding field, and/or a frame check sequence (FCS) field. Optionally, the trigger frame may further include a special user info field between the common info field and the user info list field. The user info list field may include one or more user info fields. The frame control field, the duration/ID field, the RA field, and the TA field may constitute a MAC header.

For example, the common information field may include a trigger type subfield. The trigger type subfield value may indicate a trigger frame variant, as shown in Table 1:

Trigger type subfield value Trigger frame variant 0 Basic 1 Beamforming Report Poll (BFRP) 2 MU-BAR 3 MU-RTS 4 Buffer Status Report Poll (BSRP) 5 GCR MU-BAR 6 Bandwidth Query Report Poll (BQRP) 7 NDP Feedback Report Poll (NFRP) 8 Ranging 9-18 Reserved

For example, if the value of the trigger type subfield is set to 0, the trigger frame may be a basic trigger frame. For example, if the value of the trigger type subfield is set to 2, the trigger frame may be a MU (multi-user)-BAR (block acknowledge request) trigger frame. For example, if the value of the trigger type subfield is set to 4, the trigger frame may be a BSRP trigger frame. The MU-BAR trigger frame and/or the BAR trigger frame may include a BAR type subfield. The (MU-)BAR (trigger) frame variants according to the BAR type (or the value of the BAR type subfield) are as shown in <Table 2> below:

BAR Type (MU-)BAR (Trigger) Frame variant 0 Reserved 1 Extended Compressed 2 Compressed 3 Multi-TID 4-5 Reserved 6 GCR 7-9 Reserved 10 GLK-GCR 11-15 Reserved

A BA (block acknowledge) frame can be used as a response frame to an MU-BAR trigger frame. The BA frame can include a BA control field, which can include a BA type subfield. The BA frame variations according to the BA type (or the value of the BA type subfield) are as shown in Table 3 below:

BA Type BA Frame variant 0 Reserved 1 Extended Compressed 2 Compressed 3 Multi-TID 4-5 Reserved 6 EDMG Multi-TID 7 Reserved 8 EDMG Compressed 9 Reserved 10 GLK-GCR 11 Multi-STA 12-15 Reserved

Meanwhile, STAs that have data to transmit can perform CCA (clear channel assessment) to sense the medium for a certain period (e.g., DIFS (distributed coordination function) inter-frame space) before transmitting data. At this time, if the medium is idle, the STA can perform transmission using the medium. However, if the medium is busy, it can be assumed that several STAs are already waiting to use the medium, and the STA can transmit data after waiting for a random backoff period in addition to the DIFS. At this time, the random backoff period can avoid collisions because, assuming that there are several STAs to transmit data, each STA will have a different backoff period value with probability, which will ultimately result in a different transmission time. When one STA starts transmitting, other STAs cannot use the medium. In the random backoff procedure, when a specific medium changes from busy to idle, several STAs may wait for data to be transmitted. Preparation begins. At this time, in order to minimize collisions, STAs wishing to transmit data each select a random backoff count and wait for the slot time corresponding to the selected counter. The random backoff count is a pseudo-random integer value and is selected from among values uniformly distributed in the range of [0 CW]. CW stands for contention window. The CW parameter takes the CWmin value as the initial value, but if transmission fails, the value is doubled. For example, if an ACK response is not received for a transmitted data frame, it can be considered that a collision has occurred. When the CW value has the CWmax value, the CWmax value is maintained until the data transmission is successful, and if the data transmission is successful, the CW value is reset to the CWmin value. At this time, CW, CWmin, and CWmax are set for convenience of implementation and operation. can be expressed as . Meanwhile, when the random backoff procedure starts, the STA selects a random backoff count within the range [0 CW] and continuously monitors the medium while the backoff slot is counting down. If the medium becomes busy during this time, the countdown is stopped, and when the medium becomes idle again, the countdown for the remaining backoff slots is resumed.

Figure 15 shows an example of a random backoff procedure.

Referring to Figure 15, when multiple STAs have data to send, STA3 can transmit the data frame immediately because the medium is idle for DIFS, while the remaining STAs wait for the medium to become idle. Since the medium has been idle for a while, multiple STAs will be looking for an opportunity to use the medium. Therefore, each STA selects a random backoff count, and STA 2, which selects the smallest backoff count, can transmit the data frame. After STA2 completes its transmission, the medium becomes idle again, and the STAs resume counting down the backoff interval where they were paused. STA 5, which has the next smallest random backoff count after STA 2 and paused the countdown while the medium was busy, counts down the remaining backoff slots and starts transmitting the data frame, but by chance, the random backoff count value of STA 4 overlaps, which may cause a collision. At this time, since neither STA receives an ACK response after transmitting data, the two STAs double the CW and then select a random backoff count value again.

Figure 16 illustrates an example of a procedure related to NAV setting.

Referring to FIG. 16, when a Source (e.g., AP STA/non-AP STA) that wants to transmit data transmits an RTS (request to send) frame to a Destination (e.g., AP STA/non-AP STA) that receives the data, the Destination can notify surrounding terminals that it will receive the data by transmitting a CTS (clear to send) frame. In other words, the Destination designated as a receiver through the RTS frame can transmit a CTS frame. If the Source that transmitted the RTS frame receives the CTS frame, the Source can start transmitting data to the Destination.

Meanwhile, if an STA other than the Destination designated as the receiver through the RTS frame receives the RTS frame, or if an STA other than the Source that transmitted the RTS frame receives the CTS frame, the STA may set a network allocation vector (NAV). An STA that has set a NAV may not transmit data during the NAV period, thereby avoiding collisions between the STA and the Source/Destination. On the other hand, if the Destination designated as the receiver through the RTS frame receives the RTS frame, or if the Source that transmitted the RTS frame receives the CTS frame, the Source/Destination does not set a NAV.

If a CTS frame (e.g., PHY-RXSTART.indication primitive) is not received within a certain period from the time when the RTS frame is received (e.g., the time when the MAC receives the PHY-RXEND.indication primitive corresponding to the RTS frame), STAs that have set or updated the NAV through the RTS frame may reset the NAV (e.g., to 0). The certain period may be (2*aSIFSTime + CTS_Time + aRxPHYStartDelay + 2*aSlotTime). The CTS_Time may be calculated based on the length of the CTS frame and the data rate indicated by the RTS frame.

In Fig. 16, for convenience, setting or updating NAV through RTS frame or CTS frame is illustrated, but NAV setting/resetting/updating may also be performed based on the ¡ field (e.g., duration field in MAC header of MAC frame) of various other frames, for example, non-HT PPDU, HT PPDU, VHT PPDU or HE PPDU. For example, if the RA field in the received MAC frame does not match its own address (e.g., MAC address), the STA may set/reset/update NAV according to the value of the duration field in the received MAC frame.

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

Below, the power saving mode is described.

A non-AP STA can be in one of two power management modes:

- Active mode: STAs receive and transmit frames whenever they are awake. Non-HE STAs remain awake. HE STAs remain awake unless they are unavailable. Unavailable STAs cannot receive PPDUs.

- Power saving (PS) mode: The STA enters the awake state to receive or transmit frames. Otherwise, the STA remains in the doze state.

An STA in PS mode can be in one of two power states:

- awake state: STA is fully powered.

- Doze state: STA cannot transmit or receive non-WUR PPDUs and consumes very low power.

How an STA transitions between power states is determined by its power management mode and is reflected in dot11PowerManagementMode.

The STA's power management mode is selected by the PowerManagementMode parameter in the MLMEPOWERMGT.request primitive or the MLME-MESHPOWERMGT.request primitive. When the STA updates its power management mode, the MLME issues the MLME-POWERMGT.confirm primitive or the MLMEMESHPOWERMGT.confirm primitive, respectively, indicating the success of the operation.

An STA that changes its power management mode while connected to an AP must notify the AP of this fact using the Power Management subfield within the Frame Control field of the transmitted frame. The STA must maintain its current power management mode until it notifies the AP of the power management mode change through a frame exchange sequence that includes the AP's acknowledgment. The power management mode does not change during a single frame exchange sequence. That is, the Power Management subfield is the same for all MPDUs in an A-MPDU.

An STA operating in PS mode with dot11NonTIMModeActivated set to false shall receive beacon frames periodically according to the ListenInterval parameter of the MLMEASSOCIATE.request or MLME-REASSOCIATE.request primitive and the ReceiveDTIMs parameter of the MLME-POWERMGT.request primitive, unless in WNM power save mode. An STA operating in PS mode with dot11NonTIMModeActivated set to true shall transmit at least one PS-Poll or Trigger frame individually addressed to its associated AP for each ListenInterval parameter used in the MLME primitive, starting from the last known transition of an S1G STA in non-TIM mode, unless it follows a TWT or NDP paging procedure.

WNM power saving mode enables an extended power saving mode for non-AP STAs, where non-AP STAs do not need to receive all DTIM beacons and do not need to perform GTK/IGTK/BIGTK updates. An STA in WNM sleep mode can wake up approximately once per WNM sleep interval to check whether the corresponding TIM bit is set or whether group address traffic is pending. An STA can use WNM sleep mode and PS mode simultaneously. The power management subfield of the frame control field can be set to 0 or 1 in a frame transmitted by an STA in WNM sleep mode.

I. Non-AP STA Power Management Mode

A non-AP STA shall be in active mode upon (re)association. However, if (re)association is performed using an on-channel tunneling procedure, the non-AP STA shall be considered to be in power-saving mode and in power-saving mode upon (re)association to a BSS identified by the BSSID, band ID, and channel number fields contained in the multi-band element transmitted in the on-channel tunnel request frame carrying the (re)association request frame.

An STA that transmits a frame to an AP that is not connected and expects a response must remain awake until it receives that response or the procedure times out.

To change the power management mode, an STA must notify the AP by completing a successful frame exchange initiated by the STA. This frame exchange sequence includes a management frame, extension frame, or data frame from the STA and an Ack or BlockAck frame from the AP. The Power Management subfield in the Frame Control field of the frame transmitted by the STA in this exchange indicates the power management mode that the STA should adopt upon successfully completing the frame exchange sequence, unless the Power Management subfield is reserved. A non-AP STA must not use a frame exchange sequence that does not receive an Ack or BlockAck frame from the AP, or use a BlockAckReq frame to change the power management mode. The Power Management subfield is ignored in the AP-initiated frame exchange sequence.

A non-S1G STA that transitions from doze to awake to transmit must perform CCA until a frame capable of setting a NAV is detected or the period specified by the NAVSyncDelay of the MLME-JOIN.request primitive has elapsed. An S1G STA that transitions from doze to awake to transmit must perform CCA until a frame capable of setting a RID or NAV is detected or the period specified by the NAVSyncDelay of the MLME-JOIN.request primitive has elapsed.

To change the power management mode, an STA coordinated by the MM-SME must notify the AP through a successful frame exchange sequence initiated by the STA. In this exchange, the power management subfield in the frame control field of the frame transmitted by the STA indicates the power management mode that the STA should adopt upon successful completion of the frame exchange sequence, as announced in the MMS element coordinated by the MM-SME and transmitted by the STA. To change the power management mode of a coordinated STA, a frame can be transmitted using an MMSL within the MMSL cluster established with the AP.

A non-AP S1G STA requests the PS mode type (TIM mode or non-TIM mode) through a (re)association request frame transmitted to the S1G AP.

A non-AP S1G STA requests operation in non-TIM mode by setting the Non-TIM Support field in the S1G Capabilities element of the (re)connection request frame to 1.

A non-AP S1G STA requests operation in TIM mode by setting the Non-TIM Support field in the S1G Capabilities element of the (re)connection request frame to 0.

A non-AP S1G STA checks the PS mode type (TIM mode or non-TIM mode) in the (re)association response frame received from the S1G AP.

When the S1G AP sets the non-TIM support field in the S1G operation element of the (re)association response frame to 1, the non-AP S1G STA sets dot11NonTIMModeActivated to true and operates in non-TIM mode after association, and is called a non-TIM STA.

When the S1G AP sets the non-TIM support field in the S1G operation element of the (re)association response frame to 0, the non-AP S1G STA sets dot11NonTIMModeActivated to false and operates in TIM mode after association, and is called a TIM STA.

Non-AP S1G STAs must operate in the negotiated PS mode during the connection, unless a PS mode transition is negotiated or a temporary PS mode transition occurs. STAs must update the ListenInterval parameter value used in the primitive call with the AID Response Interval field in the AID Response element of the (re)connection response frame.

An S1G STA in TIM mode receives a selected beacon frame (based on the ListenInterval parameter of the MLME-ASSOCIATE.request or MLME-REASSOCIATE.request primitive) and transmits a PS-Poll frame to the AP if the TIM element of the most recent beacon frame indicates that a BU individually addressed to that STA is buffered.

An S1G STA in non-TIM mode shall transmit at least one individually addressed PS-Poll or Trigger frame to its associated AP per receive interval and may not receive selected S1G Beacon frames (based on the ListenInterval parameter of the MLME-ASSOCIATE.request or MLME-REASSOCIATE.request primitive) unless it follows the TWT or NDP paging procedure. An S1G STA in non-TIM mode may transmit (NDP) PS-Poll frames to an S1G AP regardless of whether the S1G AP has instructed it to buffer individually addressed BUs.

II. AP Power Management

APs with dot11APPMActivated set to false or absent must operate in active mode. APs with dot11APPMActivated set to true can operate in the following power management modes:

- Active mode; and

- Power saving mode.

An AP in active mode must be awake and able to receive frames at any time.

In power saving mode, an AP with dot11APPMActivated set to true can be in one of two power states:

- awake state; and

- doze state.

An AP with dot11APPMActivated set to true can indicate that it is operating in power-saving mode in two ways:

- Set the AP PM bit to 1 in the frame control field of the S1G beacon frame, or

- Include one or more RPS elements in the S1G beacon frame indicating AP PM RAW (i.e., RAW assignment type is Simplex RAW and RAW type option is 0).

The AP shall operate in the active mode during the beacon interval or short beacon interval when the AP PM subfield of the S1G beacon frame transmitted in the TBTT or TSBTT is 0. Similarly, the AP shall operate in the active mode during one or more RAWs defined by the RPS element whose RAW assignment type is Normal RAW, Sounding RAW, Triggering Frame RAW, or Simplex RAW with RAW Type Option 1 or 2.

An AP transmitting an S1G beacon frame with the AP PM subfield set to 1 may be in doze at any time until the next TBTT or TSBTT, but must be in awake for one of the following time intervals:

- any RAW or PRAW interval set (except RAW defined by any RPS element whose RAW allocation type is Simplex RAW and whose RAW type option is 0); and

- All TWT SPs negotiated in accordance with TWT.

An AP must not remain in a doze state for a period exceeding the dot11MaxAwayDuration value. The AP must set dot11MaxAwayDuration to the lowest value obtained from the Max Away Duration field contained in the most recently received MAD element from the associated STA.

Regardless of power management mode and power state, APs must generate beacons to maintain network synchronization.

An STA that is the intended recipient of a frame transmitted by an AP with the PM Mode subfield set to 0 must consider the AP to be in active mode.

An AP that has previously transmitted a frame to one or a group of STAs with the PM bit set to 0 must transmit a frame with the PM bit set to the same set of STAs before changing its operating mode to power-save mode.

An STA that is the intended recipient of a frame in which the PM mode subfield is 1 must consider the AP to be in power-saving mode.

Below, multi-link (ML) power management is described.

Each non-AP STA belonging to a non-AP MLD operating on an active link must maintain its own power management mode and power state. Frame exchange is possible on an active link when a non-AP STA belonging to a non-AP MLD operating on that link is awake.

Figure 17 shows an example of per-link power saving operation.

Referring to Figure 17, the power saving behavior for each non-AP STA affiliated with a non-AP MLD during MLO is described. It is assumed that all TIDs are mapped to all links or a subset of links. As illustrated in Figure 17, in the initial portion, both non-AP STAs affiliated with the non-AP MLD are in active mode and participate in frame exchange with the corresponding AP on the link. Each non-AP STA affiliated with the non-AP MLD indicates that it is in active mode by setting the power management subfield (i.e., the PM bit in Figure 17) in the frame control field of the transmitted frame to 0. At some point, non-AP STA 2 affiliated with the non-AP MLD operating on Link 2 indicates to AP 2 that it is entering power saving mode (i.e., setting the PM bit to 1) and transitions to the doze state after a successful frame exchange. Non-AP STA 2 remains in doze for the remainder of the period. After a certain period of time, non-AP STA 1 enters sleep mode (i.e., sets the PM bit to 1) after a successful frame exchange. While operating in sleep mode, non-AP STA 1 wakes up to receive the beacon frame transmitted by AP 1 and determines that there is a BU for the non-AP MLD in the AP MLD. Based on this determination, non-AP STA 1 transmits a PS-Poll or U-APSD trigger frame on link 1 to notify AP 1 that it has transitioned to the active state. While in the active state, non-AP STA 1 participates in frame exchange with AP 1.

Below, the enhanced multi-link single radio (EMLSR) operation is described.

The EMLSR operation allows a non-AP MLD with multiple receive chains to receive on one or more EMLSR links an initial control frame transmitted by an AP belonging to the AP MLD in a non-HT (duplicate) PPDU when the corresponding non-AP STA belonging to the non-AP MLD is awake, and to participate in frame exchange on the link on which the initial control frame was received.

A non-AP MLD can operate in EMLSR mode on a designated set of activated links between a non-AP MLD and an associated AP MLD. A designated set of activated links to which the EMLSR mode applies is called an EMLSR link. An EMLSR link shall be indicated in the Link Bitmap subfield of the EMLSR link by setting the bit position corresponding to the Link ID value of the EMLSR link to 1 in the EMLSR Link Bitmap subfield. For EMLSR mode enabled in a single wireless non-AP MLD, an STA belonging to a non-AP MLD operating on an activated link with a bit position of 0 in the EMLSR Link Bitmap subfield shall doze if a non-AP STA belonging to a non-AP MLD operating on one of the EMLSR links is awake.

When a non-AP MLD with dot11EHTEMLSROptionActivated set to true (re)connects to an AP MLD, EMLSR mode is disabled by default.

When a non-AP MLD operates in EMLSR mode on an EMLSR link, non-AP STAs operating on the EMLSR link and associated with the non-AP MLD must not operate in dynamic SM power saving mode on the EMLSR link.

When a non-AP MLD operates in EMLSR mode with an AP MLD that supports EMLSR mode, the following applies:

a) A non-AP MLD must be able to receive on an EMLSR link by ensuring that the non-AP STAs associated with that link are awake. The receiving operation includes receiving the initial control frame of the frame exchange initiated by the CCA and the AP MLD. A non-AP STA operating on one of the EMLSR links may change its power management mode and follow power management procedures. A non-AP STA may receive on one of the EMLSR links in active mode or in PS mode when awake.

b) An AP belonging to an AP MLD that initiates a frame exchange with a non-AP MLD on one of the EMLSR links, either a data frame that is not a group address or a management frame that is not a group address, must initiate the frame exchange by sending an initial control frame to the non-AP MLD. For example, an MU-RTS trigger frame or a BSRP trigger frame can be used as the initial control frame to initiate the frame exchange.

c) A non-AP STA belonging to a non-AP MLD that is in receiving operation and receives an MU-RTS trigger frame or a BSRP trigger frame addressed to it shall transmit a response frame, except when a frame exchange initiated by an initial control frame on one of the EMLSR links overlaps with a group-addressed frame transmission on another EMLSR link on which the non-AP STA intends to receive a group-addressed frame.

d) After receiving the initial control frame of a frame exchange and transmitting an immediate response frame in response to the initial control frame, a non-AP STA belonging to a non-AP MLD that was receiving on that link shall be able to transmit or receive frames on the link on which the initial control frame was received and shall not transmit or receive on other EMLSR links until the frame exchange is completed. In addition, depending on the spatial stream capabilities, operation mode, and minimum MAC frame padding period of the padding field of the initial control frame, a non-AP STA belonging to a non-AP MLD shall be able to receive PPDUs transmitted using two or more spatial streams on the link on which the initial control frame was received a SIFS after the end of transmission of the response frame requested in the initial control frame. During the frame exchange, other APs belonging to the AP MLD shall not transmit frames to other non-AP STAs belonging to the non-AP MLD on other EMLSR links.

e) An AP belonging to an AP MLD shall transmit another initial control frame addressed to a non-AP STA belonging to a non-AP MLD if the AP has not received a response frame from this STA to the most recently transmitted frame that requires an immediate response after SIFS before the TXNAV timer expires, indicating that the AP intends to continue exchanging frames with the STA.

f) One of the non-AP STAs belonging to a non-AP MLD operating on one of the EMLSR links can initiate frame exchange with the AP MLD.

A non-AP STA belonging to a non-AP MLD operating in EMLSR mode can receive a beacon frame at the reserved beacon transmission time (e.g., TBTT).

Below, the contents of TIM (traffic indication map) are explained.

The TIM must identify STAs that have pending traffic and are buffered at the AP. This information is encoded in the partial virtual bitmap. The TIM also includes an indication of whether non-SYNRA group-addressed traffic is pending. Each STA is assigned an AID by the AP as part of the association process. AID 0 is reserved to indicate that there are buffered non-GCR-SP group-addressed BUs that are carried using MPDUs with non-SYNRA RAs but not using the group AID. The AP must identify STAs ready to forward buffered BUs by setting a bit in the TIM's partial virtual bitmap corresponding to the appropriate AID.

Two different types of TIMs are distinguished: TIM and DTIM. After the DTIM, the AP must transmit a buffered non-GCR-SP group addressing BU, which is carried using an MPDU with an RA (not a SYNRA), and then transmit the addressing frame individually. The AP can also transmit these BUs using the group AID.

APs must transmit a TIM with every beacon frame, except when the frame is scheduled to be transmitted in the TSBTT rather than the TBTT. A TIM of type DTIM, not a regular TIM, is transmitted within the beacon frame at every dot11DTIMPeriod. An S1G AP with dot11ShortBeaconInterval set to true may include a TIM in beacon frames scheduled to be transmitted in the TSBTT rather than the TBTT. An S1G AP with dot11ShortBeaconInterval set to true may transmit a TIM of type DTIM in S1G beacon frames at every dot11ShortBeaconDTIMPeriod.

FIG. 18 illustrates an example of a power management operation according to an embodiment of the present disclosure.

Referring to Figure 18, AP and STA activity is illustrated assuming that DTIMs are transmitted once every three TIMs. The top line of Figure 18 represents the time axis, and the beacon interval is indicated along with the DTIM interval of three beacon intervals. The second line represents AP activity. The AP reserves a beacon frame for transmission at each beacon interval, but the beacon frame may be delayed if there is traffic within the TBTT. This is indicated by "medium in use" in the second line. For the purposes of Figure 18, the important fact about the beacon frame is that it contains a TIM, some of which is a DTIM. The second STA, for which ReceiveDTIMs is false, does not power on its receiver for any DTIM.

The third and fourth lines of Figure 18 represent the activities of two STAs operating with different power management requirements. Both STAs power up their receivers when they need to receive a TIM. This indicates that the receiver power is ramped up before the TBTT. For example, the first STA powers up its receiver and receives a TIM in the first beacon frame. This TIM indicates that there are buffered BUs for the receiving STA. The receiving STA then generates a PS-Poll frame to trigger the transmission of the buffered BUs from the AP. BUs not addressed to the GCR-SP group are transmitted by the AP after the DTIM beacon transmission.

Meanwhile, APs typically remain active at all times to provide high throughput and fast service to connected STAs, and can exchange frames using the highest possible bandwidth and a large number of spatial streams. Because APs can be powered continuously, the need for power reduction may be relatively small. However, the actual power consumption of APs is significant, which may increase network maintenance costs. Furthermore, battery-operated APs (e.g., mobile APs) require battery life considerations. Consequently, power consumption of APs needs to be reduced. Furthermore, considering the introduction of multi-link operation in IEEE 802.11be and multi-AP cooperative networks in IEEE 802.11bn, the number of links and/or STAs operated by each multi-link device (MLD) may increase, further increasing AP power consumption. Therefore, a new method/device for reducing the power of AP needs to be designed, and an integrated framework that can be applied to all STAs can also be considered.

In the present disclosure, "frame exchange (FE)" may include frame transmission and/or reception operations between STAs. The STAs may be APs or non-AP STAs. Here, the frames may include various types of frames (e.g., data frames, control frames, management frames).

Figure 19 shows an example of EMLSR operation.

Enhanced Multi-Link Single Radio (EMLSR) was introduced in IEEE 802.11be to enable efficient multi-link operation of a single radio non-AP MLD. A non-AP MLD operating in EMLSR mode can perform listening operations on EMLSR link(s) that are awake. The listening operations may include reception of an initial control frame (ICF) and/or CCA for frame exchange(s) initiated from the AP MLD. That is, a non-AP MLD can perform listening operations on one or more links using multiple receive chains of a single radio, and exchange frames with an AP on a link where an ICF is received.

During this listening operation, the STA can reduce its power consumption by transmitting (TX)/receive (RX) PPDUs with restricted settings (e.g., non-HT (duplicate) PPDU, 20 MHz-only, 1 spatial stream) and/or performing CCA for the restricted bandwidth. That is, the operating characteristics such as the listening operation of EMLSR can be utilized in one of the power saving modes (e.g., awake, doze state). Specifically, the characteristics of the EMLSR operation as shown in FIG. 19 can be applied to individual links to reduce the power consumed by each link during the listening state. An AP/STA operating in power saving (PS) mode on one or more links can have low capability/configuration in the listening state, and can switch to a capability/configuration that can utilize a wide bandwidth and a large number of spatial streams for fast frame exchange. That is, ICFs can be defined and/or utilized similarly to EMLSR to transition these capabilities/settings. These PSs are also similar to dynamic spatial multiplexing (SM) PSs, and can be classified as dynamic PSs because they do not achieve power savings based on planned time.

Therefore, in order to reduce power consumption, a new frame sequence needs to be defined that allows an AP/STA that stays in a listening state and receives an ICF contained in a PPDU transmitted with limited capabilities/settings to exchange frames with the AP/STA that transmitted the ICF.

The present disclosure provides a frame sequence between one or more STAs operating as a flexible PS. Specifically, the present disclosure provides a frame sequence for an AP operating as a flexible PS to perform downlink (DL) multi-user (MU) transmissions to multiple connected STAs, and provides an ICF for initiating the frame sequence. Through this frame sequence/ICF, the AP can perform DL MU transmissions while reducing power consumption.

In the present disclosure, a dynamic PS may mean a PS in which the PS mode/state is changed based on detection of a specific event and/or transmission/reception of a specific frame.

For example, when an STA operating as a dynamic PS (e.g., an AP/non-AP STA) detects an ICF transmission event (e.g., detects that there is data to transmit/receive) in the listening state, transmits an ICF, and/or receives an ICF, the STA may transition to the frame exchange state and perform frame exchange in the frame exchange state. For example, when the STA receives an ICF in the listening state, the STA may transition from the listening state to the frame exchange state, perform CCA/backoff for a wide bandwidth, and transmit an initial control response (ICR) based on the normal capabilities/settings. When the frame exchange is completed (e.g., when an ACK frame is transmitted/received), the STA may transition back to the listening state.

In the present disclosure, a listening state may mean a state in which an STA (e.g., an AP/non-AP STA) operates with limited capabilities/configurations, receives ICFs based on the limited capabilities/configurations, and/or performs CCA/backoff for limited bandwidth.

In the present disclosure, a frame exchange state may refer to a state in which an STA (e.g., an AP/non-AP STA) operates with normal capabilities/configurations and performs frame exchange based on the normal capabilities/configurations. For example, the frame exchange state may include an awake state.

The specific designations (names) proposed in this disclosure may be changed and are not limited thereto.

FIG. 20 illustrates an example of a method performed by an AP for dynamic power saving according to an embodiment of the present disclosure.

Referring to FIG. 20, in step S2001, the AP may enter a listening state of a dynamic power save (PS) mode.

In step S2003, the AP, in a listening state, can detect downlink data to be transmitted to one or more STAs (stations).

In step S2005, the AP may transmit an initial control frame (ICF) to one or more STAs to initiate downlink transmission in a flexible PS mode based on detecting downlink data to be transmitted.

In step S2007, after transmitting the ICF, the AP may transmit downlink data to one or more STAs in a frame exchange state of a fluid PS mode.

According to various embodiments, the listening state may be a state in which the AP performs listening operations based on restricted capabilities. The frame exchange state may be a state in which the AP performs frame exchanges based on normal capabilities.

According to various embodiments, the listening operation may include at least one of: monitoring the reception of an ICF, receiving an ICF, or performing a channel access procedure for a limited bandwidth. The channel access procedure may include at least one of a clear access assessment (CCA) or a back-off.

According to various embodiments, the limited capability may include at least one of a limited bandwidth or a limited number of spatial streams. The general capability may include at least one of a bandwidth greater than the limited bandwidth or a number of spatial streams greater than the limited number of spatial streams.

According to various embodiments, the general capability may include at least one of a capability supported by the STA or a capability supported by the AP.

According to various embodiments, the capabilities supported by the STA may include the maximum capabilities of the STA. The capabilities supported by the AP may include the maximum capabilities of the AP.

According to various embodiments, the AP may transition from a listening state to a frame exchange state based on detection of downlink data to be transmitted. In the frame exchange state, the AP may transmit an ICF to one or more STAs based on general capabilities.

According to various embodiments, the ICF may include at least one of a block acknowledge request (BAR) frame, a multi-user (MU)-BAR trigger frame, or a buffer status report poll (BSRP) trigger frame.

According to various embodiments, the BAR Type subfield of the BAR frame may be set to one of the reserved values to indicate that the ICF is an ICF for initiating downlink transmission in the flexible PS mode.

According to various embodiments, the AP may receive a response frame for the ICF. After receiving the response frame, the AP may transmit downlink data to one or more STAs based on general capabilities in a frame exchange state.

According to various embodiments, the AP may transition from a listening state to a frame exchange state in response to transmission of an ICF or reception of a response frame.

According to various embodiments, the response frame may include information indicating that the response frame is an initial control response (ICR) frame for an ICF for initiating downlink transmission in a flexible PS mode.

According to various embodiments, the response frame may include a block acknowledge (BA) frame. The BA type subfield of the BA frame may be set to one of the reserved values to indicate that the response frame is an ICR frame for an ICF for initiating downlink transmission in a flexible PS mode.

According to various embodiments, an AP may receive an ACK (acknowledgement) frame for DL data from one or more STAs based on general capabilities in a frame exchange state. In response to receiving an ACK frame, the AP may transition from a frame exchange state to a listening state.

According to various embodiments, the one or more STAs may include at least one of an STA in a dynamic PS mode, or an STA that has transmitted information to the AP indicating that the power management mode is active.

FIG. 21 illustrates an example of signal flow between an AP and a STA for dynamic power saving according to an embodiment of the present disclosure.

Referring to FIG. 21, in step S2101, the AP may enter a listening state of a dynamic power save (PS) mode.

In step S2103, the AP, in a listening state, can detect downlink data to be transmitted to the STA.

In step S2105, the STA may receive an initial control frame (ICF) from the AP to initiate downlink transmission in a flexible PS mode. The AP may transmit the ICF to the STA based on the detection of downlink data to be transmitted.

In step S2107, after receiving the ICF, the STA may receive downlink data from the AP. After transmitting the ICF, the AP may transmit downlink data to the STA in a frame exchange state of the flexible PS mode.

Below, a detailed implementation for dynamic power saving in DL MU transmission is described.

The present disclosure defines a frame sequence for DL MU transmission between an AP and STAs when one or more STAs are operating as a floating PS, and the type of an initial control frame (ICF) in the frame sequence. The present disclosure addresses a frame sequence for DL MU transmission depending on whether a non-AP STA is operating as a floating PS, when the AP is operating as a floating PS.

I. ICF for DL MU transmission in fluid PS operation

An ICF needs to be designed for DL MU transmission in fluid PS operation.

In some implementations, among the trigger frames (TFs), the MU-BAR (i.e., type = 2) trigger frame can be utilized as an ICF for flexible PS operation. For example, a new type of MU-BAR TF can be implemented that can be utilized for DL MU transmission in flexible PS operation by utilizing reserved values among the BAR types (e.g., 4-5 or 7-9 or 11-15).

FIG. 22 illustrates an example of an ICF format for DL MU transmission in a fluid PS operation according to an embodiment of the present disclosure. In FIG. 22 , the names of fields and/or the number of bits may be changed, and new fields may be added to support fluid PS operation.

Referring to FIG. 22, the BAR type of an MU-BAR TF can indicate that the corresponding MU-BAR TF is an ICF/MU-BAR TF for DL MU transmission in flexible PS operation. For example, one of the reserved values (e.g., 4-5 or 7-9 or 11-15) of the BAR type (sub)field can be utilized to indicate that the corresponding MU-BAR TF is transmitted as an ICF in flexible PS operation or an ICF/MU-BAR TF for DL MU transmission in flexible PS operation. A new type can be defined to utilize the reserved type (i.e., the BAR type corresponding to the reserved value) to indicate that the corresponding MU-BAR TF is an ICF/MU-BAR TF for DL MU transmission in flexible PS operation or an ICF in flexible PS operation.

Additionally, a new type of block acknowledge (BA) frame may be implemented to respond to MU-BAR TF.

FIG. 23 illustrates an example of a response frame format for ICF in a fluid PS operation according to an embodiment of the present disclosure.

Referring to Figure 23, a BA frame can be used as a response frame to an ICF/MU-BAR TF transmitted for DL MU transmission in a flexible PS operation. The names and/or number of bits of fields can be changed, and new fields can be added to support the flexible PS operation.

The BA type of a BA frame may indicate that the BA frame is a response frame to an ICF/MU-BAR TF transmitted for DL MU transmission in flexible PS operation. For example, one of the reserved values (e.g., 4-5 or 9 or 12-15) of the BA type (sub)field may be utilized to indicate that the BA frame is a response frame to an ICF/MU-BAR TF transmitted for DL MU transmission in flexible PS operation. A new type may be defined to utilize the reserved type (i.e., the BA type corresponding to the reserved value) to indicate that the BA frame is a response frame to an MU-BAR TF for DL MU transmission in flexible PS operation.

II. Procedure for DL MU Transmission in Fluid PS Operation

Below, the frame sequence for DL MU transmission depending on whether a non-AP STA operates as a dynamic PS when the AP operates as a dynamic PS is described.

1. When AP and non-AP STAs operate as dynamic PSs.

In some implementations, non-AP STAs can support the AP's dynamic PS operation. For example, non-AP STAs can transmit ICFs (e.g., control frames) to the AP. For example, non-AP STAs can receive the ICFs from the AP and transmit a response frame to the ICF after a SIFS.

In some implementations, an AP operating as a dynamic PS may be aware that the recipient STAs of a DL MU transmission are not currently in a doze state (e.g., at the time of transmitting the ICF to those STAs). For example, when the AP is in a listening state for a dynamic PS, non-AP STAs may always be in a listening or awake state.

FIG. 24 illustrates a first example of a frame sequence for DL MU transmission in a fluid PS operation according to an embodiment of the present disclosure. In FIG. 24, it is assumed that APs and non-AP STAs operate in a fluid PS.

Referring to FIG. 24, an AP connected to STAs supporting dynamic AP PS may perform listening operations (e.g., ICF reception and/or channel access procedures (e.g., (random) backoff/CCA)) based on limited capabilities/configurations (e.g., 20 MHz, 1 SS, non-HT (duplicate) PPDU TX/RX) in a listening state to reduce power consumption. When DL data for multiple STAs is transmitted from an upper layer, the AP may initiate a random backoff procedure and acquire a TXOP through contention. The AP that acquires the TXOP may transmit a PPDU (e.g., non-HT (duplicate) PPDU, 20 MHz, 1 SS) with limited capabilities/configurations including an ICF (e.g., MU-BAR TF with BAR type set to ICF, BSRP TF) to non-AP STAs to transition the non-AP STAs from a listening state to a frame exchange state.

For example, an AP can transition from a listening state to a state with higher capabilities (e.g., awake state/frame exchange state) for transmitting an ICF, and can transmit an ICF in the high-capability state. In this case, the ICF contained in a PPDU with limited capabilities/configurations (e.g., non-HT (duplicate) PPDU) can be transmitted over a bandwidth greater than 20 MHz, but the receiving non-AP STAs in the listening state can receive the PPDU at 20 MHz.

For example, an AP may transition from a listening state to a high-capability state (e.g., awake state/frame exchange state) in response to transmission of an ICF (e.g., MU-BAR TF, BSRP TF with BAR type set to ICF) and/or reception of a response frame to an ICF (e.g., BA frame with BA type set to ICF).

STAs receiving an ICF can change their capabilities/configurations for TX/RX based on information contained in a recently received beacon frame, preset information, and/or information contained in an ICF transmitted from the AP. STAs that switch from a listening state to a higher capability/configuration (e.g., 80 MHz/1 SS or 160 MHz/2 SS) for frame exchange with the AP can transmit a response frame (e.g., a BA frame) to the ICF to the AP. An AP that receives response frames from non-AP STAs can initiate DL MU transmission and transmit PPDU(s) containing DL data to multiple non-AP STAs in a state with a higher capability. When BA frames indicating the end of frame exchange between the AP and STAs are transmitted from STAs, the AP and STAs can switch back to the listening state to reduce unnecessary power consumption.

2. When the AP operates as a dynamic PS, and the power management mode of at least one non-AP STA may be different.

In some implementations, non-AP STAs can support the AP's dynamic PS operation. For example, non-AP STAs can transmit ICFs to the AP. For example, non-AP STAs can receive the ICF from the AP and transmit a response frame to the ICF after a SIFS.

In some implementations, an AP operating in a dynamic PS may not be aware of the state of the recipient STAs of a DL MU transmission unless it receives separate signaling from the recipient STAs (e.g., PS-Poll frame, PM bit = 0 or 1, ICF). For example, when the AP is in a listening state for a dynamic PS, non-AP STAs may operate in a separate power management mode and may be in separate/independent power management states. For example, if a particular STA transmits a frame with PM bit = 0, the AP may recognize that the STA is in an awake state until the STA transmits a frame with PM bit = 1.

FIG. 25 illustrates a second example of a frame sequence for DL MU transmission in a flexible PS operation according to an embodiment of the present disclosure. In FIG. 25 , it is assumed that the AP operates in a flexible PS and that the power management mode of at least one non-AP STA may be different.

Referring to FIG. 25, an AP connected to STAs supporting dynamic AP PS may perform listening operations (e.g., ICF reception and/or CCA) with limited capabilities/configurations (e.g., 20 MHz, 1 SS, non-HT (duplicate) PPDU TX/RX) in a listening state to reduce power consumption. A specific STA(s) (e.g., non-AP STA 1) may notify the AP that it is currently in an awake state by transmitting a frame with PM bit = 0. The frame with PM bit = 0 at this time may be transmitted in a PPDU with limited capabilities/configurations. When DL data for multiple STAs is transmitted from an upper layer, the AP may perform a random backoff procedure and acquire a TXOP through contention. An AP that has acquired a TXOP may transmit a PPDU with limited capabilities/configurations (e.g., non-HT (duplicate) PPDU, 20 MHz, 1 SS) containing an ICF (e.g., MU-BAR TF with BAR type set to ICF, BSRP TF) to target non-AP STAs to transition at least one STA (e.g., non-AP STA) from a listening state to a frame exchange state and/or to initiate DL (MU) transmission. The target STAs at this time may be STAs operating in a dynamic PS and/or STAs that have signaled an awake state by transmitting a frame with PM bit = 0.

For example, an AP can transition from a listening state to a state with higher capabilities (e.g., awake state/frame exchange state) for transmitting an ICF, and can transmit an ICF in the high-capability state. In this case, the ICF contained in a PPDU with limited capabilities/configurations (e.g., non-HT (duplicate) PPDU) can be transmitted over a bandwidth greater than 20 MHz, but the receiving non-AP STAs in the listening state can receive the PPDU at 20 MHz.

For example, an AP may transition from a listening state to a high-capability state (e.g., awake state/frame exchange state) in response to transmission of an ICF (e.g., MU-BAR TF, BSRP TF with BAR type set to ICF) and/or reception of a response frame to an ICF (e.g., BA frame with BA type set to ICF).

STAs that receive an ICF (e.g., MU-BAR TF, BSRP TF with BAR type set to ICF) can change their capabilities/configurations for TX/RX based on information contained in a recently received beacon frame, preset information, and/or information contained in an ICF transmitted from the AP. An STA operating in a dynamic PS (e.g., Non-AP STA 2) that switches from a listening state to a higher capability/configuration (e.g., 80 MHz/1 SS or 160 MHz/2 SS) for frame exchange with the AP can transmit a response frame (e.g., BA frame) to the ICF to the AP. In addition, an STA in an awake state that supports the dynamic PS operation of the AP (e.g., Non-AP STA 1) can also transmit a response frame (e.g., BA frame) to the ICF to the AP. An AP that receives a response frame from a non-AP STA can initiate DL MU transmission in a state with high capability (e.g., frame exchange state/awake state) and transmit PPDU(s) containing DL data to multiple non-AP STAs. When a BA frame indicating the end of frame exchange between the AP and STAs is transmitted from the STAs, the AP and some STAs operating in a dynamic PS can switch back to the listening state to reduce unnecessary power consumption. Similarly, STAs that wish to enter a doze state can transmit a BA frame with the PM bit set to 1 and then enter the doze state, thereby achieving greater power savings.

The present disclosure defines a frame sequence for performing DL MU transmissions to multiple STAs connected to an AP operating as a fluid PS.

For example, when AP and non-AP STAs operate as dynamic PS, AP/STA can operate in a listening state with limited capabilities/configurations other than the period in which frame exchange is performed, thereby reducing unnecessary power consumption.

For example, if an AP operates as a dynamic PS and at least one non-AP STA has a different power management mode, the AP or some STAs can reduce power consumption in a listening state, and some non-AP STAs in a doze state can achieve greater power savings.

The technical features of the present disclosure described above can be applied to various devices and methods. For example, the technical features of the present disclosure described above can be performed/supported by the devices of FIG. 1 and/or FIG. 5. For example, the technical features of the present disclosure described above can be applied only to a portion of FIG. 1 and/or FIG. 5. For example, the technical features of the present disclosure described above can be implemented based on the processing chip (114, 124) of FIG. 1, or based on the processor (111, 121) and memory (112, 122) of FIG. 1, or based on the processor (510) and memory (520) of FIG. 5.

For example, the processor (121) and/or the processing chip (124) of FIG. 1 may be configured to execute instructions stored in the memory (122) to perform operations performed by the AP in the present disclosure. The operations include: entering a listening state of a dynamic power save (PS) mode; detecting, in the listening state, downlink data to be transmitted to one or more STAs; transmitting, based on the detection of the downlink data to be transmitted, an initial control frame (ICF) to initiate downlink transmission in the dynamic PS mode to the one or more STAs; and transmitting, after transmitting the ICF, the downlink data to the one or more STAs in a frame exchange state of the dynamic PS mode.

For example, the processor (111), the processing chip (114) of FIG. 1, and/or the processor (510) of FIG. 5 may be configured to execute instructions stored in the memory (112, 520) to perform operations performed by the STA in the present disclosure. The operations include: receiving an initial control frame (ICF) for initiating downlink transmission in a dynamic power save (PS) mode from an access point (AP); and receiving downlink data from the AP after the STA receives the ICF, wherein the ICF is transmitted from the AP based on the AP detecting the downlink data to be transmitted to the STA in a listening state of the dynamic PS mode, and wherein the downlink data is transmitted from the AP while the AP is in a frame exchange state of the dynamic PS mode.

The technical features of the present disclosure can be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by the present disclosure is at least one computer-readable recording medium containing instructions that are executed by at least one processor.

For example, the CRM may be the memory (122) of FIG. 1 and/or a separate external memory/storage medium/disk. The CRM may store commands that perform operations performed by the AP in the present disclosure based on being executed by a processor (e.g., the processor (121) and/or the processing chip (124) of FIG. 1). The operations include: entering a listening state of a dynamic power save (PS) mode; detecting, in the listening state, downlink data to be transmitted to one or more STAs; transmitting, based on the detection of the downlink data to be transmitted, an initial control frame (ICF) to initiate downlink transmission in the dynamic PS mode to the one or more STAs; and transmitting, after transmitting the ICF, the downlink data to the one or more STAs in a frame exchange state of the dynamic PS mode.

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 commands that perform operations performed by the STA in the present disclosure based on being executed by a processor (e.g., the processor (111), the processing chip (114) of FIG. 1, and/or the processor (510) of FIG. 5). The operations include: receiving an initial control frame (ICF) from an access point (AP) to initiate downlink transmission in a dynamic power save (PS) mode; And the STA includes an operation of receiving downlink data from the AP after receiving the ICF, wherein the ICF is transmitted from the AP based on the AP detecting the downlink data to be transmitted to the STA in a listening state of the flexible PS mode, and the downlink data is transmitted from the AP while the AP is in a frame exchange state of the flexible PS mode.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

The present disclosure may have various advantageous effects.

For example, when AP and non-AP STAs operate as dynamic PS, AP/STA can operate in a listening state with limited capabilities/configurations other than the period in which frame exchange is performed, thereby reducing unnecessary power consumption.

For example, if an AP operates as a dynamic PS and at least one non-AP STA has a different power management mode, the AP or some STAs can reduce power consumption in a listening state, and some non-AP STAs in a doze state can achieve greater power savings.

The beneficial effects that can be achieved through specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, various technical effects may be understood and/or derived from the present disclosure by those skilled in the art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure.

The claims set forth in this disclosure may be combined in various ways. For example, the technical features of the method claims of this disclosure may be combined and implemented as a device, and the technical features of the device claims of this disclosure may be combined and implemented as a method. Furthermore, the technical features of the method claims of this disclosure and the technical features of the device claims of this disclosure may be combined and implemented as a device, and the technical features of the method claims of this disclosure and the technical features of the device claims of this disclosure may be combined and implemented as a method.

Claims (20)

A step in which an access point (AP) enters a listening state in a dynamic power save (PS) mode; A step of detecting downlink data to be transmitted to one or more STAs (stations) by the AP in the listening state; A step of transmitting an initial control frame (ICF) to initiate downlink transmission in the flexible PS mode to one or more STAs based on detecting the downlink data to be transmitted by the AP; and A method comprising a step of transmitting the downlink data to one or more STAs in a frame exchange state of the fluid PS mode after the AP transmits the ICF. In claim 1, the listening state is a state in which the AP performs a listening operation based on a restricted capability, The above frame exchange state is a state in which the AP performs frame exchange based on normal capabilities. In claim 2, the listening operation includes at least one of an operation of monitoring reception of an ICF, an operation of receiving an ICF, or an operation of performing a channel access procedure for a limited bandwidth. A method wherein the channel access procedure includes at least one of a clear access assessment (CCA) or a back-off. In claim 2, the limited capability comprises at least one of a limited bandwidth or a limited number of spatial streams, A method wherein the general capability comprises at least one of a bandwidth greater than the limited bandwidth or a number of spatial streams greater than the number of limited spatial streams. A method according to claim 2, wherein the general capability includes at least one of a capability supported by the STA or a capability supported by the AP. In claim 5, the capability supported by the STA includes the maximum capability of the STA, A method in which the capabilities supported by the AP include the maximum capabilities of the AP. In claim 1, further comprising a step of switching from the listening state to the frame exchange state based on detecting the downlink data to be transmitted by the AP, A method in which the step of transmitting the ICF comprises a step in which the AP transmits the ICF to one or more STAs based on general capabilities in the frame exchange state. A method according to claim 1, wherein the ICF includes at least one of a BAR (block acknowledge request) frame, a MU (multi-user)-BAR trigger frame, or a BSRP (buffer status report poll) trigger frame. A method according to claim 8, wherein the BAR type subfield of the BAR frame is set to one of reserved values to indicate that the ICF is an ICF for starting downlink transmission in the flexible PS mode. In claim 1, the AP further comprises a step of receiving a response frame for the ICF, A method in which the step of transmitting the downlink data includes a step in which the AP, after receiving the response frame, transmits the downlink data to one or more STAs based on general capabilities in the frame exchange state. A method according to claim 10, further comprising a step of switching from the listening state to the frame exchange state in response to the transmission of the ICF or the reception of the response frame. A method according to claim 10, wherein the response frame includes information indicating that the response frame is an ICR (initial control response) frame for an ICF for starting downlink transmission in the flexible PS mode. In claim 10, the response frame includes a BA (block acknowledge) frame, A method in which the BA type subfield of the above BA frame is set to one of the reserved values to indicate that the response frame is an ICR frame for an ICF for starting downlink transmission in the above flexible PS mode. In claim 1, the step of the AP receiving an ACK (acknowledge) frame for the DL data from one or more STAs based on the general capability in the frame exchange state; and A method further comprising a step of the AP switching from the frame exchange state to the listening state in response to reception of the ACK frame. A method according to claim 1, wherein the one or more STAs include at least one of an STA in the dynamic PS mode or an STA that has transmitted information indicating that the power management mode is active to the AP. In AP(access point), Transmitter and receiver; memory; and At least one processor functionally coupled with the transceiver and the memory, The memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An action to enter a listening state in dynamic power save (PS) mode; In the above listening state, an operation of detecting downlink data to be transmitted to one or more STAs (stations); An operation of transmitting an initial control frame (ICF) to initiate downlink transmission in the flexible PS mode to one or more STAs based on detecting the downlink data to be transmitted; and An AP including an operation of transmitting the downlink data to one or more STAs in a frame exchange state of the fluid PS mode after transmitting the ICF. In the device, at least one processor; and At least one memory functionally coupled with at least one processor, The at least one memory stores instructions that perform operations based on being executed by the at least one processor, the operations being: An action to enter a listening state in dynamic power save (PS) mode; In the above listening state, an operation of detecting downlink data to be transmitted to one or more STAs (stations); An operation of transmitting an initial control frame (ICF) to initiate downlink transmission in the flexible PS mode to one or more STAs based on detecting the downlink data to be transmitted; and A device including an operation of transmitting the downlink data to one or more STAs in a frame exchange state of the fluid PS mode after transmitting the ICF. A non-transitory computer readable medium (CRM) storing program code that implements instructions that perform operations based on being executed by at least one processor, wherein the operations are: An action to enter a listening state in dynamic power save (PS) mode; In the above listening state, an operation of detecting downlink data to be transmitted to one or more STAs (stations); An operation of transmitting an initial control frame (ICF) to initiate downlink transmission in the flexible PS mode to one or more STAs based on detecting the downlink data to be transmitted; and A CRM including an operation of transmitting the downlink data to one or more STAs in a frame exchange state of the fluid PS mode after transmitting the ICF. A step in which a STA (station) receives an initial control frame (ICF) to initiate downlink transmission in a dynamic power save (PS) mode from an AP (access point); and A step of receiving downlink data from the AP after the STA receives the ICF, The above ICF is transmitted from the AP based on the AP detecting the downlink data to be transmitted to the STA in the listening state of the fluid PS mode, A method in which the above downlink data is transmitted from the AP while the AP is in a frame exchange state of the fluid PS mode. In STA(station), Transmitter and receiver; memory; and At least one processor functionally coupled with the transceiver and the memory, The memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An operation of receiving an initial control frame (ICF) to initiate downlink transmission in a dynamic power save (PS) mode from an access point (AP); and The above STA includes an operation of receiving downlink data from the AP after receiving the ICF, The above ICF is transmitted from the AP based on the AP detecting the downlink data to be transmitted to the STA in the listening state of the fluid PS mode, The above downlink data is transmitted from the AP to the STA while the AP is in a frame exchange state of the fluid PS mode.