Cross-link power management in multi-link operation

Abstract

A wireless communication network includes an access point (AP) multilink device (MLD) and a non-AP MLD. The STA of the non-AP MLD may inform the AP MLD of a change in power management mode and / or power saving state for another STA affiliated to the same non-AP MLD via cross-link signaling. The AP MLD may inform the non-AP MLD of its ability to receive cross-link signaling for a change in power management mode and / or power saving state, and the time required to handle cross-link signaling for a change in power management mode and / or power saving state.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to multi-link operations in wireless communication systems, for example but not limited to. Background Art

[0002] Since the late 1990s, wireless local area network (WLAN) technology has been evolving toward increasing data rates and continues to grow in various markets such as home, enterprise, and hotspots. WLAN allows devices to access the Internet in the 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz frequency bands. WLAN is based on the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standards. The IEEE 802.11 family of standards is designed to increase speed, reliability, and extend the operating range of wireless networks.

[0003] WLAN devices are increasingly required to support various delay-sensitive or real-time applications, such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and driverless vehicles. In order to implement the extremely low latency and extremely high throughput required for such applications, multi-link operation (MLO) has been proposed for WLAN. WLAN is formed in a limited area such as a home, school, apartment, or office building by WLAN devices. Each WLAN device may have one or more stations (STAs), such as access point (AP) STA and non-access point (non-AP) STA.

[0004] MLO enables a non-AP multi-link device (MLD) to establish multiple links with an AP MLD. Each of the multiple links can independently implement channel access and frame exchange between the non-AP MLD and the AP MLD, which can reduce latency and increase throughput.

[0005] The description set forth in the “Background” section should not be admitted to be prior art merely because it is set forth in the “Background” section. The “Background” section may describe aspects or embodiments of the present disclosure. Summary of the invention

[0006] Solution to the problem

[0007] One embodiment of the present disclosure may provide a non-AP MLD associated with an access point (AP) multi-link device (MLD) in a wireless network. The non-AP MLD may include at least two stations (STAs) and at least one processor coupled to the at least two STAs. The at least one processor is configured to determine a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD. The at least one processor is configured to send a frame to a first AP on a first link established between a first STA attached to the non-AP MLD and a first AP attached to the AP MLD, the frame including a field indicating a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD.

[0008] In some embodiments, the field includes a first subfield that indicates whether the field includes a power management mode change indication or a power saving state change indication.

[0009] In some embodiments, the field includes a second subfield indicating one or more links of the AP MLD associated with a power management mode change or a power saving state change.

[0010] In some embodiments, the power management mode change is a change from an active mode to a power saving mode or from a power saving mode to an active mode, and the power saving state change is a change from a sleep state to an awake state or from an awake state to a sleep state.

[0011] In some embodiments, the frame includes a third subfield indicating whether the power management mode is transitioning from the active mode to the power saving mode or from the power saving mode to the active mode.

[0012] In some embodiments, the power management mode change is determined based on the first subfield and the third subfield.

[0013] In some embodiments, the at least one processor is further configured to participate in a frame exchange with at least one AP attached to the APMLD on each link between the non-AP MLD and the AP MLD when the field indicates that one or more STAs transition to an active mode or awake state, and wherein the at least one AP is associated with at least one STA among the one or more STAs.

[0014] In some embodiments, the at least one processor is further configured to receive capability information from the AP MLD, the capability information indicating whether the AP MLD supports receiving a power management mode change indication or a power saving state change indication for one or more STAs affiliated with the non-AP MLD.

[0015] In some embodiments, at least one processor is further configured to receive processing delay information indicating an amount of time to process a power management mode change indication or a power saving state change indication.

[0016] In some embodiments, at least one processor is configured to perform a power management mode change or a power saving state change for one or more STAs at a time determined based on an amount of time indicated by the processing delay information.

[0017] One embodiment of the present disclosure may provide an AP multi-link device (MLD) associated with a non-access point (AP) multi-link device (MLD) in a wireless network. The AP MLD may include at least two APs and at least one processor coupled to the at least two APs. The at least one processor is configured to receive a frame from a first STA on a first link established between a first STA attached to the non-AP MLD and a first AP attached to the AP MLD, the frame including a field indicating a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD. The at least one processor is configured to: in response to determining that one or more STAs transition to an active mode or awake state based on the field included in the frame, initiate a frame exchange with at least one STA of the one or more STAs on each link between the AP MLD and the non-AP MLD. The at least one processor is configured to: in response to determining that one or more STAs transition to a sleep state based on the field included in the frame, initiate buffering of a bufferable unit of at least one STA of the one or more STAs.

[0018] In some embodiments, the field includes a first subfield that indicates whether the field includes a power management mode change indication or a power saving state change indication.

[0019] In some embodiments, the field includes a second subfield indicating one or more links of the AP MLD associated with a power management mode change or a power saving state change.

[0020] In some embodiments, the power management mode change is a change from an active mode to a power saving mode or from a power saving mode to an active mode, and the power saving state change is a change from a sleep state to an awake state or from an awake state to a sleep state.

[0021] In some embodiments, the frame includes a third subfield indicating whether the power management mode is transitioning from the active mode to the power saving mode or from the power saving mode to the active mode.

[0022] In some embodiments, at least one processor is configured to determine a power management mode change based on the first subfield and the third subfield.

[0023] In some embodiments, the at least one processor is further configured to send capability information to the non-AP MLD, the capability information indicating whether the AP MLD supports receiving a power management mode change indication or a power saving state change indication for one or more STAs attached to the non-AP MLD.

[0024] In some embodiments, at least one processor is further configured to send processing delay information indicating an amount of time to process the power management mode change indication or the power saving state change indication.

[0025] In some embodiments, at least one processor is configured to initiate frame exchange with at least one of the one or more STAs or initiate buffering of a bufferable unit of at least one of the one or more STAs at a time determined based on the processing delay information. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An example of a wireless network according to an embodiment is shown.

[0027] Figure 2A An example of an AP according to an embodiment is shown.

[0028] Figure 2B An example of a STA according to an embodiment is shown.

[0029] Figure 3 An example of multi-link operation according to an embodiment is shown.

[0030] Figure 4 An example of a TID (traffic identifier) ​​to link mapping element according to an embodiment is shown.

[0031] Figure 5A and Figure 5B An example of multi-link operation according to an embodiment is shown.

[0032] Fig. 6A and Figure 6B An example of multi-link operation according to an embodiment is shown.

[0033] Figure 7 An example of the MLD Capability and Operation fields in a Basic Multilink Element according to an embodiment is shown.

[0034] Fig. 8AAn example table of control ID subfield values ​​of a HE (high efficiency) variant HT (high throughput) control field according to an embodiment is shown.

[0035] Figure 8B An example of a control information subfield format in a LI (link indication) control subfield according to an embodiment is shown.

[0036] Figure 8C An example of a subtype subfield of the LI control subfield according to an embodiment is shown.

[0037] Fig.8D Another example of the control information subfield format in the LI control subfield according to an embodiment is shown.

[0038] Fig.9A An example of an MLPM (Multi-link Power Management) notification frame format according to an embodiment is shown.

[0039] Fig. 9B An example of a protected EHT (extremely high throughput) action field value according to an embodiment is shown.

[0040] Fig. 9C An example of an MLPM notification field format according to an embodiment is shown.

[0041] Fig.10 A flow chart illustrating an example process for AP MLD according to an embodiment is shown.

[0042] Fig.11 A flow chart illustrating an example process for non-AP MLD according to an embodiment is shown.

[0043] In one or more embodiments, not all components depicted in each figure may be required, and one or more embodiments may include additional components not shown in the figures. The arrangement and type of components may be varied without departing from the scope of the subject disclosure. Additional components, different components, or fewer components may be utilized within the scope of the subject disclosure. DETAILED DESCRIPTION

[0044] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various embodiments, rather than being intended to represent the only embodiment in which the subject technology can be practiced. More specifically, the detailed description includes specific details for the purpose of providing a thorough understanding of the subject matter of the present invention. As will be appreciated by those skilled in the art, in the case where the described embodiments do not depart from the scope of the present disclosure, they can be modified in various ways. Accordingly, the drawings and descriptions are considered to be illustrative in nature, rather than restrictive. Similar reference numerals represent similar elements.

[0045] The following description is directed to certain embodiments for the purpose of describing the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The examples in the present disclosure are based on WLAN communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard (including the IEEE 802.11be standard and any future amendments to the IEEE 802.11 standard). However, the described embodiments may be implemented in a communications network capable of operating in accordance with IEEE 802.11 standards, Bluetooth standards, Global System for Mobile communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), 5G NR (New Radio), AMPS (advanced mobile phone The term "cellular" refers to any device, system or network (such as a system utilizing 3G, 4G, 5G, 6G or further implementations thereof) that sends and receives radio frequency (RF) signals or other known signals for communicating within a wireless, cellular or internet of things (IoT) network.

[0046] Depending on the network type, other well-known terms may be used instead of "access point" or "AP", such as "router" or "gateway". For convenience, the term "AP" is used in the present disclosure to refer to a network infrastructure component that provides wireless access to a remote terminal. In a WLAN, considering that an AP also competes for a wireless channel, an AP may also be referred to as a STA. Moreover, depending on the network type, other well-known terms may be used instead of "station" or "STA", such as "mobile station", "subscriber station", "remote terminal", "user device", "wireless terminal" or "user equipment". For convenience, the terms "station" and "STA" are used in the present disclosure to refer to a remote wireless device that wirelessly accesses an AP or competes for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smart phone) or is generally considered to be a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0047] Multi-link Operation (MLO) is a key feature currently being developed by the standards body for the next generation Extremely High Throughput (EHT) Wi-Fi system in IEEE 802.11be. Wi-Fi devices that support MLO are called Multi-link Devices (MLDs). With MLO, it is possible for a non-AP MLD to discover, authenticate, associate, and establish multiple links with an AP MLD. Channel access and frame exchange can be performed on each link between an AP MLD and a non-AP MLD.

[0048] Figure 1 An example of a wireless network 100 according to an embodiment is shown. Figure 1 The embodiment of the wireless network 100 shown is for illustration purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0049] like Figure 1 As shown, the wireless network 100 may include multiple wireless communication devices. Each wireless communication device may include one or more stations (STA). A STA may be a logical entity that is a single addressable instance of a medium access control (MAC) layer and a physical (PHY) layer interface to a wireless medium. A STA may be classified into an access point (AP) STA and a non-access point (non-AP) STA. An AP STA may be an entity that provides access to a distributed system service via a wireless medium for associated STAs. A non-AP STA may be a STA that is not included in an AP-STA. For simplicity of description, an AP STA may be referred to as an AP, and a non-AP STA may be referred to as a STA. In Figure 1In the example of , APs 101 and 103 are wireless communication devices that can each include one or more AP STAs. In such an embodiment, APs 101 and 103 can be AP multi-link devices (MLDs). Similarly, STAs 111-114 are wireless communication devices that can each include one or more non-AP STAs. In such an embodiment, STAs 111-114 can be non-AP MLDs.

[0050] APs 101 and 103 communicate with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. AP 101 provides wireless access to network 130 for multiple stations (STAs) 111-114 having a coverage area 120 of AP 101. APs 101 and 103 may communicate with each other and with STAs using Wi-Fi or other WLAN communication technologies.

[0051] Depending on the network type, other well-known terms may be used instead of "access point" or "AP", such as "router" or "gateway". For convenience, the term "AP" is used in the present disclosure to refer to a network infrastructure component that provides wireless access to a remote terminal. In a WLAN, considering that an AP also competes for a wireless channel, an AP may also be referred to as a STA. Moreover, depending on the network type, other well-known terms may be used instead of "station" or "STA", such as "mobile station", "subscriber station", "remote terminal", "user device", "wireless terminal" or "user equipment". For convenience, the terms "station" and "STA" are used in the present disclosure to refer to a remote wireless device that wirelessly accesses an AP or competes for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smart phone) or is generally considered to be a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0052] exist Figure 1 , dashed lines illustrate the approximate extents of coverage areas 120 and 125 of APs 101 and 103, where coverage areas 120 and 125 are shown as generally circular for purposes of illustration and explanation. It should be clearly understood that coverage areas associated with APs, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the APs.

[0053] As described in more detail below, one or more APs may include circuitry and / or programming for managing MU-MIMO (MultiUser- Multiple Input Multiple Output) and OFDMA (Orthogonal Frequency-Division Multiple Access) channel sounding in a WLAN. Figure 1 One example of a wireless network 100 is shown, but may be Figure 1 Various changes may be made. For example, the wireless network 100 may include any number of APs and any number of STAs in any suitable arrangement. Moreover, the AP 101 may communicate directly with any number of STAs and provide these STAs with wireless broadband access to the network 130. Similarly, each of the APs 101 and 103 may communicate directly with the network 130 and provide the STAs with direct wireless broadband access to the network 130. In addition, the APs 101 and / or 103 may provide access to other or additional external networks (such as an external telephone network or other types of data networks).

[0054] Figure 2A An example of an AP 101 according to an embodiment is shown. Figure 2A The illustrated embodiment of AP 101 is for illustration purposes only and Figure 1 The APs 103 may have the same or similar configurations. However, APs have a variety of configurations, and Figure 2A The scope of the present disclosure is not limited to any particular implementation of the AP.

[0055] like Figure 2A As shown, the AP 101 may include multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. The AP 101 may also include a controller / processor 224, a memory 229, and a backhaul or network interface 234. The RF transceivers 209a-209n receive incoming RF signals from the antennas 204a-204n, such as signals transmitted by STAs in the network 100. The RF transceivers 209a-209n down-convert the incoming RF signals to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 219, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry 219 sends the processed baseband signal to the controller / processor 224 for further processing.

[0056] The TX processing circuit 214 receives analog or digital data (such as voice data, network data, email, or interactive electronic game data) from the controller / processor 224. The TX processing circuit 214 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceivers 209a-209n receive the outgoing processed baseband or IF signals from the TX processing circuit 214 and up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 204a-204n.

[0057] The controller / processor 224 may include one or more processors or other processing devices that control the overall operation of the AP 101. For example, the controller / processor 224 may control the reception of uplink signals and the transmission of downlink signals through the RF transceivers 209a-209n, the RX processing circuit 219, and the TX processing circuit 214 according to well-known principles. The controller / processor 224 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 224 may support beamforming or directional routing operations, in which outgoing signals from multiple antennas 204a-204n are weighted differently to effectively direct the outgoing signals in the desired direction. The controller / processor 224 may also support OFDMA operations, in which outgoing signals are assigned to different subcarrier subsets for different recipients (e.g., different STAs 111-114). The controller / processor 224 may support any of a variety of other functions in the AP 101, including a combination of DL MU-MIMO and OFDMA in the same transmit opportunity. In some embodiments, the controller / processor 224 may include at least one microprocessor or microcontroller. The controller / processor 224 may also execute programs and other processes residing in the memory 229, such as an OS (operating system). The controller / processor 224 may move data into or out of the memory 229 as required by the executed process.

[0058] The controller / processor 224 is also coupled to a backhaul or network interface 234. The backhaul or network interface 234 allows the AP 101 to communicate with other devices or systems over a backhaul connection or over a network. The interface 234 can support communication over any suitable (multiple) wired or wireless connections. For example, the interface 234 can allow the AP 101 to communicate over a wired or wireless local area network or a wired or wireless connection to a larger network (such as the Internet). The interface 234 can include any suitable structure that supports communication over a wired or wireless connection, such as an Ethernet or RF transceiver. The memory 229 is coupled to the controller / processor 224. A portion of the memory 229 may include RAM (random access memory), and another portion of the memory 229 may include flash memory or other ROM (read-only memory).

[0059] As described in more detail below, AP 101 may include circuitry and / or programming for managing a channel sounding procedure in a WLAN. Figure 2A An example of AP 101 is shown, but the Figure 2A For example, AP101 may include Figure 2A Any number of each component shown. As a specific example, the AP may include multiple interfaces 234, and the controller / processor 224 may support routing functions to route data between different network addresses. As another example, although shown as including a single instance of TX processing circuitry 214 and a single instance of RX processing circuitry 219, the AP 101 may include multiple instances of each of the TX processing circuitry 214 and the RX processing circuitry 219 (such as one instance per RF transceiver). Alternatively, such as in a conventional AP, only one antenna and RF transceiver path may be included. Moreover, the components may be combined, further subdivided, or omitted. Figure 2A There are various components in it, and additional components can be added according to specific needs.

[0060] like Figure 2A As shown, in some embodiments, the AP 101 may be an AP MLD including a plurality of APs 202a-202n. Each AP 202a-202n is attached to the AP MLD 101 and includes a plurality of antennas 204a-204n, a plurality of radio frequency (RF) transceivers 209a-209n, a transmit (TX) processing circuit 214, and a receive (RX) processing circuit 219. Each AP 202a-202n may independently communicate with the controller / processor 224 and other components of the AP MLD 101. Figure 2AEach AP 202a-202n is shown with a separate multiple antennas, but each AP 202a-202n may share multiple antennas 204a-204n rather than requiring separate multiple antennas.Each AP 202a-202n may represent a physical (PHY) layer and a lower medium access control (MAC) layer.

[0061] Figure 2B An example of STA 111 according to an embodiment is shown. Figure 2B The embodiment of STA 111 shown is for illustration purposes and Figure 1 STAs 111-114 may have the same or similar configurations. However, STAs have a variety of configurations, and Figure 2B The scope of the present disclosure is not limited to any particular implementation of a STA.

[0062] like Figure 2B As shown, STA 111 may include antenna(s) 205, RF transceiver 210, TX processing circuit 215, microphone 220, and RX processing circuit 225. STA 111 may also include speaker 230, controller / processor 240, input / output (I / O) interface (IF) 245, touch screen 250, display 255, and memory 260. Memory 260 may include operating system (OS) 261 and one or more applications 262.

[0063] The RF transceiver 210 receives incoming RF signals transmitted by the APs of the network 100 from the antenna(s) 205. The RF transceiver 210 down-converts the incoming RF signals to generate an IF or baseband signal. The IF or baseband signal is sent to the RX processing circuit 225, which generates a processed baseband signal by filtering, decoding and / or digitizing the baseband or IF signal. The RX processing circuit 225 sends the processed baseband signal to the speaker 230 (such as for voice data), or to the controller / processor 240 for further processing (such as for web browsing data).

[0064] The TX processing circuit 215 receives analog or digital voice data from the microphone 220 or other outgoing baseband data (such as network data, email, or interactive electronic game data) from the controller / processor 240. The TX processing circuit 215 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 210 receives the outgoing processed baseband or IF signal from the TX processing circuit 215 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 205.

[0065] The controller / processor 240 may include one or more processors and execute a basic OS program 261 stored in the memory 260 to control the overall operation of the STA 111. In one such operation, the controller / processor 240 controls the reception of downlink signals and the transmission of uplink signals through the RF transceiver 210, the RX processing circuit 225, and the TX processing circuit 215 according to well-known principles. The controller / processor 240 may also include a processing circuit configured to provide management of a channel sounding procedure in the WLAN. In some embodiments, the controller / processor 240 may include at least one microprocessor or microcontroller.

[0066] The controller / processor 240 is also capable of executing other processes and programs resident in the memory 260, such as operations for managing channel sounding programs in the WLAN. The controller / processor 240 can move data into or out of the memory 260 as needed for the execution process. In some embodiments, the controller / processor 240 is configured to execute multiple applications 262, such as applications for channel sounding, including feedback calculations based on received null data packet announcements (NDPA) and null data packets (NDP) and sending beamforming feedback reports in response to trigger frames (TF). The controller / processor 240 can operate multiple applications 262 based on the OS program 261 or in response to signals received from the AP. The controller / processor 240 is also coupled to the I / O interface 245, which provides the STA 111 with the ability to connect to other devices (such as laptops and handheld computers). The I / O interface 245 is a communication path between these accessories and the main controller / processor 240.

[0067] The controller / processor 240 is also coupled to an input 250 (such as a touch screen) and a display 255. An operator of the STA 111 can use the input 250 to enter data into the STA 111. The display 255 can be a liquid crystal display, a light emitting diode display, or other display capable of rendering text and / or at least limited graphics (such as from a website). A memory 260 is coupled to the controller / processor 240. A portion of the memory 260 can include random access memory (RAM), and another portion of the memory 260 can include flash memory or other read-only memory (ROM).

[0068] although Figure 2B An example of STA 111 is shown, but the Figure 2B For example, they can be combined, further subdivided, or omitted Figure 2B101 , and additional components may be added as needed. In a particular example, STA 111 may include any number of antennas 205 for MIMO communication with AP 101. In another example, STA 111 may not include voice communication, or controller / processor 240 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although Figure 2B The STA 111 is illustrated as being configured as a mobile phone or smart phone, but the STA may be configured to operate as other types of mobile or stationary devices.

[0069] like Figure 2B As shown, in some embodiments, STA 111 may be a non-AP MLD including multiple STAs 203a-203n. Each STA 203a-203n is attached to the non-AP MLD 111 and includes (multiple) antennas 205, RF transceivers 210, TX processing circuits 215, and RX processing circuits 225. Each STA 203a-203n may independently communicate with the controller / processor 240 and other components of the non-AP MLD 111. Figure 2B Each STA 203a-203n is shown with a separate antenna, but each STA 203a-203n may share antenna 205, rather than requiring a separate antenna. Each STA 203a-203n may represent a physical (PHY) layer and a lower medium access control (MAC) layer.

[0070] Figure 3 An example of a multi-link communication operation according to an embodiment is shown. The multi-link communication operation can be used for the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. Figure 3 In the example, the AP MLD 310 can be Figure 1 The wireless communication devices 101 and 103 in the embodiment, and the non-AP MLD 220 may be Figure 1 One of the wireless communication devices 111-114 in.

[0071] like Figure 3As shown, AP MLD 310 may include multiple subordinate APs, including, for example, AP 1, AP 2, and AP 3. Each subordinate AP may include a PHY interface to a wireless medium (Link 1, Link 2, or Link 3). AP MLD 310 may include a single MAC service access point (SAP) 318 through which the subordinate APs of AP MLD 310 communicate with a higher layer (Layer 3 or Network Layer). Each subordinate AP of AP MLD 310 may have a different MAC address (lower MAC address) than any other subordinate AP of AP MLD 310. AP MLD 310 may have an MLD MAC address (higher MAC address), and the subordinate APs share a single MAC SAP 318 to Layer 3. Therefore, the subordinate APs share a single IP address, and Layer 3 identifies AP MLD 310 by assigning a single IP address.

[0072] The non-AP MLD 320 may include a plurality of subordinate STAs, including, for example, STA 1, STA 2, and STA 3. Each subordinate STA may include a PHY interface (Link 1, Link 2, or Link 3) to a wireless medium. The non-AP MLD 320 may include a single MAC SAP 328 through which the subordinate STAs of the non-AP MLD 320 communicate with a higher layer (Layer 3 or Network Layer). Each subordinate STA of the non-AP MLD 320 may have a different MAC address (lower MAC address) from any other subordinate STA of the non-AP MLD 320. The non-AP MLD 320 may have an MLD MAC address (higher MAC address), and the subordinate STAs share the single MAC SAP 328 to Layer 3. Therefore, the subordinate STAs share a single IP address, and Layer 3 identifies the non-AP MLD 320 by assigning a single IP address.

[0073] The AP MLD 310 and the non-AP MLD 320 can establish multiple links between their affiliated APs and STAs. In this example, AP 1 and STA 1 can establish link 1 operating in the 2.4 GHz band. Similarly, AP 2 and STA 2 can establish link 2 operating in the 5 GHz band, and AP 3 and STA 3 can establish link 3 operating in the 6 GHz band. Each link can independently implement channel access and frame exchange between the AP MLD 310 and the non-AP MLD 320, which can increase data throughput and reduce latency. When associating with the AP MLD on a set of links (setup link), a unique association identifier (AID) is assigned to each non-AP device.

[0074] In order to prioritize the transmission of different types of traffic identified by traffic identifiers (TIDs) between established links, the non-AP MLD 320 may negotiate a TID-to-link mapping with the AP MLD 310. The TID-to-link mapping allows the APMLD 310 and the non-AP MLD 320 to determine how to allocate frames belonging to the TID for transmission on each established link in the uplink direction and the downlink direction, respectively. When at least one TID associated with the non-AP MLD 320 is mapped to an established link in the uplink direction or the downlink direction, the link is referred to as an enabled link for the non-AP MLD 320. By default, all TIDs are mapped to all established links between the AP MLD 310 and the non-AP MLD 320, and the mapping is referred to as a default TID-to-link mapping. During association, the non-AP MLD 320 may negotiate a non-default mapping of TIDs to established links using a negotiation procedure by including a TID-to-link mapping element in an association request frame or a reassociation request frame. The non-default mapping may be the case where all TIDs are mapped to the same subset of established links, or the case where not all TIDs are mapped to the same subset of established links. The AP MLD 310 may also use a broadcast procedure to indicate a switch to a non-default mapping for all associated non-AP MLDs. In the default mapping mode, all TIDs are mapped to all established links for downlinks and uplinks, and all established links are enabled. When TID-to-link mapping negotiation does not occur or is unsuccessful, the non-AP MLD 320 operates in the default mapping mode.

[0075] Figure 4 An example of a TID-to-link mapping element 400 is shown according to an embodiment. Figure 4This example may be applicable to the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. The TID-to-link mapping element 400 may indicate on which links frames belonging to each TID may be exchanged.

[0076] like Figure 4 As shown, the TID to link mapping element 400 may include an element ID field, a length field, an element ID extension field, a TID to link mapping control field, a mapping switch time field, an expected duration field, and an optional TID n link mapping field.

[0077] The element ID field and the element ID extension field may include information to identify the TID-to-link mapping element 400. The length field may indicate the length of the TID-to-link mapping element 400.

[0078] The TID to link mapping control field may include a direction subfield, a default link mapping subfield, a mapping switch time present subfield, an expected duration present subfield, a link mapping size subfield, a reserved subfield, and an optional link mapping present indicator subfield. The direction subfield may indicate whether the TID to link mapping element 400 is used for a downlink frame, an uplink frame, or both. For example, for a downlink frame, the direction subfield may be set to 0; for an uplink frame, the direction subfield may be set to 1; and for a frame sent on both the downlink and the uplink, the direction subfield may be set to 2. The default link mapping subfield may indicate whether the TID to link mapping element 400 represents a default TID to link mapping. For example, for a default mapping, this subfield may be set to 1; and for a non-default mapping, this subfield may be set to 0. The mapping switch time present subfield may indicate whether the mapping switch time field is present in the TID to link mapping element 400. The expected duration present subfield may indicate whether the expected duration field is present in the TID to link mapping element 400. The Link Map Size subfield may indicate the length of the TID n Link Map field. The Link Map Presence Indicator subfield may indicate whether the TID n Link Map field is present in the TID to Link Map element 400.

[0079] The Mapping Switch Time field is present when the TID-to-Link Mapping element 400 is sent in a beacon or probe response frame by an AP attached to an AP MLD, and the indicated TID-to-link mapping has not yet been established.

[0080] The expected duration field may indicate the duration for which the proposed TID-to-link mapping is expected to be valid when the mapping switch time field is present, and the remaining duration for which the proposed TID-to-link mapping is expected to be valid when the mapping switch time field is not present.

[0081] The TID n Link Mapping field (e.g., where n = 0, 1, … , 7) may indicate which links of TID n are allowed to be transmitted. The TID n Link Mapping field may carry a bitmap of the links to which TID n is mapped. The TID n Link Mapping field may not be present when the Default Link Mapping subfield of the TID to Link Mapping Control field represents a default TID to link mapping. For example, when the Direction subfield is set to 0, the Default Link Mapping subfield is set to 0, and the TID 0 Link Mapping field is configured to 10000…0, the configuration indicates that downlink data corresponding to TID 0 is transmitted on Link 1.

[0082] The TID-to-link mapping element 400 may be included in various management frames, such as a beacon frame, an association request / response frame, a reassociation request / response frame, or a probe response frame.

[0083] In order to allow non-AP devices to save power, there may be several power management solutions. For example, a non-AP MLD STA may be able to operate and switch to two possible states: an awake state and a sleep state. In the awake state, the non-AP MLD STA can continuously monitor the channel and send and receive frames to / from the AP device or the non-AP device. However, in the sleep state, the non-AP MLD STA may not be able to send or receive frames. Various power saving mechanisms have been defined in the IEEE 802.11 standard, such as normal power saving (PS) mode, automatic power saving delivery (APSD), wireless network management (WNM) power saving mode, power saving multi-polling mode, spatial multiplexing PS, independent basic services set (IBSS) power saving and very high throughput (VHT) transmission opportunity (TXOP) power saving. In these power saving mechanisms, a STA may send a physical layer (PHY) protocol data unit (PPDU) with the power management (PM) bit in the frame control field set to 1 to indicate to the AP MLD that the STA is transitioning from active mode to power saving mode. Similarly, when the STA intends to transition from power saving mode to active mode, the STA may send a PPDU with the PM bit set to 0. In some embodiments, a non-AP STA may be in one of two power management modes (active mode and power saving mode). In active mode, the STA may receive and send frames at any time to remain in an awake state. In power saving mode, the STA may enter an awake state to receive or send frames, otherwise remain in a dormant state. When the STA is in a dormant state, it may not be able to sense the channel and may therefore not know the current state of the channel or the end of an existing transmission. This condition may be referred to as a loss of medium synchronization. Therefore, when the STA immediately sends a frame in such a condition that it is considered to have lost medium synchronization, it may cause a conflict with an existing transmission. Accordingly, a STA that transitions from the sleep state to the awake state to transmit a frame will perform a clear channel assessment (CCA) procedure until it detects a frame by which it can set its network allocation vector (NAV) timer, or until the time period indicated by NAVSyncDelay has elapsed. Only then can the STA transmit the frame.

[0084] When a STA is in a dormant state, the AP associated with the AP MLD buffers "bufferable packets" that are addressed to the STA but cannot be delivered to another STA associated with the same non-AP MLD that is in an awake state or active mode. Such buffered packets may be referred to as buffered traffic or bufferable units (BUs) and are delivered to the STA when the STA returns to an awake state.

[0085] In order to indicate their pending BUs to all associated non-AP devices via broadcast or multicast signaling, each AP attached to the APMLD periodically includes a traffic information map (TIM) element in the beacon frame. Optionally, the multilink traffic indication element can be included in the beacon frame sent by the AP. Alternatively, each AP of the AP MLD can send these elements as a separate periodic broadcast TIM frame. Therefore, non-AP devices can learn about the pending traffic buffered at the AP by listening to the TIM element and / or the multilink traffic indication element in the beacon frame.

[0086] A STA attached to a non-AP device may send frames such as a power save (PS) poll frame and a U-APSD trigger frame to indicate to the AP that it is awake and ready to receive frames. This indication may not be necessary for the STA to send frames in the uplink direction. When an AP attached to an AP MLD receives a PS-poll frame or a U-APSD trigger frame from a STA attached to an associated non-AP MLD in power save mode, the AP may send the buffered BU to the STA if the buffered BU is available and has not been discarded for implementation-related reasons. Otherwise, the AP may send a QoS null frame.

[0087] After initiating a frame exchange sequence with a STA of a non-AP MLD in power saving mode to send a BU, the AP may utilize the More Data subfield in the Frame Control field of the transmitted frame to inform the non-AP MLD whether to buffer more individually addressed BUs for the non-AP MLD. These buffered BUs correspond to data frames that map a traffic identifier (TID) to a corresponding link or management frame that is not a transmit power control (TPC) request frame or a link measurement request frame. When there are no pending buffered BUs, the More Data subfield may be set to 0, and the STA may return to sleep state after completing the frame exchange sequence.

[0088] When a STA attached to a non-AP MLD transitions from a sleep state to an awake state, it may not be able to send a PS-Poll frame or a U-APSD trigger frame immediately after waking up due to loss of medium synchronization, as described above. Further, because the power saving operation is performed on a per-link basis, each STA that transitions from a sleep state to an awake state must independently send a respective PS-Poll frame or a U-APSD trigger frame to indicate that it has transitioned to an awake state. This may result in increased complexity and increased overhead. Further, these constraints may also apply to power management mode switching indications, which are similarly performed on a per-link basis in multi-link operations.

[0089] The present disclosure provides a method by which a STA of a non-AP MLD notifies an AP MLD of a change in a power saving state or power management mode of another STA attached to the same non-AP MLD. The present disclosure also provides a method for an AP MLD to indicate a time required for information exchange between APs. It may take a period of time, after which the indicated cross-link power management mode change or cross-link power saving state change will take effect.

[0090] Figure 5A and Figure 5B An example of multi-link operation according to an embodiment is shown. Figure 5A and Figure 5B In the example, the AP MLD 510 may include two subordinate APs (eg, AP 1 and AP 2), and the non-AP MLD 520 may include two subordinate STAs (eg, STA 1 and STA 2). The AP MLD 510 and the non-AP MLD 520 may be respectively Figure 3 . AP1 and STA1 can establish link 1, and AP2 and STA2 can establish link 2. Each link can independently implement channel access and perform frame exchange between AP MLD 510 and non-AP MLD 520. In this example, it is assumed that non-AP MLD 520 is in power saving mode on both link 1 and link 2.

[0091] refer to Figure 5A, when operating in power saving mode, STA 1 may wake up to receive a beacon frame sent from AP 1. The beacon frame may include a TIM element indicating that there is a BU mapped to link 2 at AP MLD 510. Therefore, non-AP MLD 520 determines that AP MLD 510 has a BU for STA 2. Based on this determination, STA 2 in a dormant state may wake up after a time period indicated by NAVSyncDelay and send a PS-Poll frame to AP 2. NAVSyncDelay is a delay time to be used before sending when transitioning from a dormant state to an awake state. The PS-Poll frame indicates to AP 2 that it has transitioned to an awake state. Then, STA 2 participates in a frame exchange with AP 2 to obtain buffered BUs via link 2. After a successful frame exchange, STA 2 may transition to a dormant state. In this example, STA 2, which has transitioned from a dormant state to an awake state, may not be able to send a PS-Poll frame immediately upon waking up due to the delay caused by NAVSyncDelay. This may cause some delay in STA2 retrieving the buffered BU on link 2.

[0092] refer to Figure 5B , when operating in power saving mode, STA 1 may wake up to receive a beacon frame sent from AP 1. The beacon frame may include a TIM element indicating that there is a BU mapped to link 2 at AP MLD 510. Therefore, non-AP MLD 520 determines that AP MLD 510 has buffered BUs for STA 2. Based on this determination, STA 2 wakes up and transitions to an awake state. At the same time, STA 1 may send a cross-link PS-poll frame on behalf of STA 2 indicating that STA 2 is in an awake state, and AP2 may immediately deliver the buffered BU to STA 2 via link 2. Subsequently, STA 2 immediately participates in a frame exchange with AP 2 to obtain the buffered BU via link 2. After a successful frame exchange, STA 2 may transition to a sleep state. In this example, there is no delay caused by NAVSyncDelay, as Figure 5A As shown, STA 1 has entered the awake state to listen to the beacon frame and immediately sends a cross-link PS-Poll frame on behalf of STA 2.

[0093] Fig. 6A and Figure 6B An example of multi-link operation according to an embodiment is shown. Fig. 6A and Figure 6B In the example, the AP MLD 610 may include two subordinate APs (eg, AP 1 and AP 2), and the non-AP MLD 620 may include two subordinate STAs (eg, STA 1 and STA 2). The AP MLD 610 and the non-AP MLD 620 may be respectively Figure 3 . AP1 and STA 1 can establish link 1, and AP 2 and STA 2 can establish link 2. Each link can independently implement channel access and perform frame exchange between AP MLD 610 and non-AP MLD 620. In this example, it is assumed that non-AP MLD 520 is in power saving mode on both link 1 and link 2. Each STA of non-AP MLD 620 can independently transition between power saving mode and active mode. For example, the STA of non-AP MLD 620 can immediately transition from active mode to power saving mode after successfully performing frame exchange. In addition, the STA of non-AP MLD 620 can transition back to active mode at a later time to send frames.

[0094] refer to Fig. 6A , during the initial portion of the illustration, both STA 1 and STA 2 of the non-AP MLD 620 are in power saving mode. At some time, both STA 1 and STA 2 of the non-AP MLD 620 may want to transition to active mode, and each STA of the non-AP MLD 620 performs a respective procedure for power management mode transition. More specifically, each STA of the non-AP MLD 620 may independently indicate to its respective AP (i.e., AP 1 or AP 2) that it is entering active mode by setting the PM bit in the frame control field of the transmitted PPDU to 0. Subsequently, each STA of the non-AP MLD 620 may perform frame exchanges with its corresponding AP of the AP MLD 610. After a certain period of time, each STA may re-enter power saving mode by setting the PM bit to 1 after a successful frame exchange. In this example, each STA of the non-AP MLD 620 must independently send a frame to its respective AP to indicate a change in power management mode. This process may result in unnecessary overhead for the non-AP MLD 620 and the APMLD 610. Figure 6B An example solution to the aforementioned problem is provided.

[0095] refer to Figure 6B , during the initial portion of the diagram, both STA 1 and STA 2 of the non-AP MLD 620 are in power saving mode. At some point, both STA 1 and STA 2 of the non-AP MLD 620 may want to transition to active mode. Fig. 6AIn the example of FIG. 1 , STA 2 of non-AP MLD 620 may send a cross-link power management (PM) indication to AP 2 of AP MLD 610 via link 2. The cross-link PM indication may indicate to AP 2 that both STA 1 and STA 2 of non-AP MLD 620 transition from power saving mode to active mode. In response to the cross-link PM indication, AP MLD 610 may send traffic on either link. In this example, AP 1 of AP MLD 610 may initiate a frame exchange with STA 1 of non-AP MLD 620 via link 1. After a successful frame exchange, STA 1 of AP MLD 610 may send a cross-link PM indication to AP 1 of AP MLD 610 via link 1. The cross-link PM indication may indicate to AP 1 that both STA 1 and STA 2 of non-AP MLD 620 transition from active mode back to power saving mode. Subsequently, both STA 1 and STA 2 re-enter power saving mode.

[0096] The AP MLD may be able to receive a PM mode switching indication for a first STA attached to an associated non-AP MLD via a frame sent by a second STA attached to the same non-AP MLD. In the present disclosure, the indication may be referred to as a "cross-link PM mode switching (or change) indication" or a "cross-link PM mode indication". Similarly, the AP MLD may be able to receive a power saving state switching indication for a first STA attached to the same non-AP MLD via a frame sent by a second STA attached to the associated non-AP MLD. The indication may be referred to as a "cross-link power saving state switching (or change) indication" or a "cross-link power saving state indication".

[0097] The AP MLD may indicate these capabilities of receiving a cross-link PM mode switch indication and / or a cross-link power saving state switch indication by introducing one or more new subfields or bits in the MLD Capability and Operation field of the basic multilink element. For example, there may be a new subfield in the MLD Capability and Operation field called a Multi-Link Power Management (MLPM) Support subfield, in which support for receiving a cross-link PM mode switch indication and a cross-link power saving state switch indication is jointly indicated.

[0098] Figure 7 An example of the MLD Capability and Operation fields in a Basic Multilink Element sent by an AP attached to an AP MLD according to an embodiment is shown.

[0099] exist Figure 7In the MLD capability and operation field 700, the maximum number of simultaneous links subfield, the SRS (singler response scheduling) support subfield, the TID to link mapping negotiation support subfield, the STR (simultaneous transmit and receive) frequency separation / AP MLD type indication subfield, the AAR (AP assistance request) support subfield, the MLPM support subfield and the MLPM delay subfield.

[0100] The Maximum Number of Simultaneous Links subfield may indicate the maximum number of STAs attached to the MLD that support simultaneous transmission or reception of frames on their respective links. The SRS Support subfield may indicate support for receiving frames carrying the SRS Control subfield. The TID-To-Link Mapping Negotiation Support subfield may indicate support for TID-To-Link Mapping (TTLM) negotiation. The STR Frequency Separation / AP MLD Type Indication subfield may include an STR frequency separation indication and an APMLD type indication. The STR frequency separation indication may indicate the minimum frequency gap between any two links recommended by the non-AP MLD for STR operation. The frequency gap is specified as the difference between the nearest frequency edges of the two links. The AP MLD Type Indication may indicate the type of the AP MLD. In particular, it may indicate whether the AP MLD is a non-simultaneous transmit and receive (NSTR) mobile AP MLD. The AAR Support subfield may indicate support for receiving frames with the AAR Control subfield.

[0101] The MLPM Support subfield may indicate support for receiving a cross-link PM mode switching indication and a cross-link power saving state switching indication. More specifically, when the AP MLD can receive a cross-link PM mode switching indication and a cross-link power saving state switching indication, the MLPM Support subfield may be set to 1. Otherwise, it may be set to 0. In some embodiments, the MLPM Support subfield may indicate support for receiving a cross-link PM mode switching indication and / or a cross-link power saving state switching indication. In some embodiments, all APs attached to the same AP MLD may indicate the same capability associated with the MLPM Support subfield.

[0102] MLPM delay may indicate the amount of time required for the AP MLD to process and successfully apply a cross-link PM mode switch indication and / or a cross-link power saving state switch indication. MLPM delay is an inter-AP processing delay to process and successfully apply a cross-link PM mode switch indication and / or a cross-link power saving state switch indication.

[0103] In some embodiments, a management information base (MIB) variable (eg, dot11MLPMImplemented) may be assigned to this feature. It may be set to true when MLPM capability is supported. Otherwise, it may be set to false.

[0104] In some embodiments, the definition and encoding of the MLPM Support subfield may be implemented as shown in Table 1 below.

[0105] [Table 1]

[0106]

[0107] In some implementations, support for cross-link PM mode indication and cross-link power saving state indication may be mandatory for AP MLD. Therefore, MLPM capability indication may not be necessary.

[0108] In some embodiments, the AP MLD may indicate inter-AP processing delay, e.g. Figure 7 The MLPM delay in, i.e., the amount of time required to process and successfully apply the cross-link PM mode indication and the cross-link power saving state indication received at the first AP attached to the AP MLD. The inter-AP processing delay can also be utilized by STAs associated with a second AP attached to the same AP MLD. In some embodiments, the MLPM delay can be a predetermined amount of time so that any AP MLD with MLPM support capability must comply with it. In another embodiment, the value of the MLPM delay can be AP-specific and can be indicated in the common information field of the basic multi-link element sent by the AP MLD. For example, the value of the MLPM delay can be included in the MLPM delay subfield in the EML capability subfield of the common information field of the basic multi-link element or the MLD capability and operation subfield. Figure 7An example is shown in which the MLPM Delay subfield is included in the MLD Capabilities and Operations field in a Basic Multilink Element sent by an AP attached to an AP MLD. In some embodiments, the MLPM Delay subfield may be implemented as shown in Table 2 below. In some embodiments, if the Basic Multilink Element is sent by a non-AP MLD or by an AP MLD with the MLPM Support subfield set to 0, the MLPM Delay subfield may be reserved. In some embodiments, the value of the MLPM Delay may be link specific and may be indicated in the Link Information field of the Basic Multilink Element.

[0109] [Table 2]

[0110]

[0111] In some embodiments, a cross-link PM mode indication and a cross-link power saving state indication for a first STA attached to a non-AP MLD may be carried in a new A (aggregation) control field sent by a second STA attached to the same non-AP MLD. The new A-control field may be a link indication (LI) control subfield. The LI control subfield may be sent by the second STA in a HE variant HT control field within a QoS data frame or a QoS null frame. In some embodiments, the LI control subfield may be a generic A control subfield, such as FIG. 8A to FIG. 8D shown.

[0112] Fig. 8A An example table of control ID subfield values ​​for the HE variant HT control field according to an embodiment is shown. Fig. 8A As shown, the LI control subfield may be defined as a new A control field as well as other new A control fields, such as an AP Assistance Request (AAR) control subfield.

[0113] Figure 8B An example of the control information subfield format in the LI control subfield according to an embodiment is shown. In addition, Figure 8C An example of a subtype subfield of the LI control subfield according to an embodiment is shown. The control information subfield in the LI control subfield can be used by a non-AP MLD STA to notify the AP MLD of a link ID set of the STAs affiliated with the non-AP MLD associated with a power management mode change and / or a power saving state switching change.

[0114] refer to Figure 8B, the control information subfield format in the LI control subfield may include a subtype subfield, a reserved subfield, and a link ID bitmap subfield. The bit sizes of these subfields may be 3 bits, 1 bit, and 16 bits, respectively. The subtype subfield may indicate the purpose of the link ID bitmap subfield. More specifically, it may indicate whether the link ID bitmap subfield includes an MLPM (Multi-link Power Management) indication or a Multi-link PS Poll (MLPP) indication. The link ID bitmap subfield may indicate a link ID associated with an MLPM indication or an MLPP indication.

[0115] refer to Figure 8C , when the subtype value is set to 0, the link ID bitmap subfield may include an MLPM indication, which may indicate a link ID for which a power management mode is indicated. Additionally, when the subtype value is set to 1, the link ID bitmap subfield may include an MLPP indication, which may indicate a link ID for which a change from a sleep state to an awake state is indicated. Other values ​​may be reserved for potential future purposes.

[0116] When transmitted by a STA attached to a non-AP MLD to an AP attached to an AP MLD, the LI Control subfield with the MLPP subtype may indicate the link ID of the STA attached to the non-AP MLD that is transitioning from the sleep state to the awake state. In some embodiments, a value of 1 in bit position i of the Link ID Bitmap subfield may indicate to the AP MLD that the STA attached to the non-AP MLD operating on the link with link ID equal to i is transitioning from the sleep state to the awake state. In addition, a value of 0 in a bit position of the Link ID Bitmap subfield may indicate to the AP MLD that the STA attached to the non-AP MLD operating on the link with link ID equal to i is not transitioning from the sleep state to the awake state.

[0117] In one embodiment, the LI control subfield with the MLPP subtype may not be transmitted by the AP MLD. However, in another embodiment where the power saving mode is applicable to the AP MLD, the LI control subfield with the MLPP subtype may be transmitted by the APMLD.

[0118] In one embodiment, the non-AP MLD may ensure that a STA indicated as 1 in the Link ID Bitmap subfield of the LI Control subfield with the MLPP subtype transitions to the awake state within the MLPM delay duration from the successful transmission of the LI Control subfield. The non-AP MLD may obtain the MLPM delay duration from the capability information in the basic multilink element previously transmitted from the associated AP MLD. In another embodiment, the non-AP MLD may ensure that a STA indicated as 1 in the Link ID Bitmap subfield of the LI Control subfield with the MLPP subtype transitions to the awake state before transmitting the LI Control subfield.

[0119] When an AP affiliated with an AP MLD receives a frame including a LI control subfield with an MLPP subtype from a non-AP MLD, the AP may share power saving state switching information with other APs operating on the link indicated as "1" in the Link ID Bitmap subfield. After receiving the LI control subfield with an MLPP subtype, these other APs may schedule transmission of buffered BUs or traffic for their respective STAs affiliated with the non-AP MLD operating on their respective links immediately after the duration specified by the MLPM Delay subfield.

[0120] When the LI control subfield with the MLPM subtype is sent by a STA attached to a non-AP MLD to an AP attached to an AP MLD, it may indicate the link ID of the STA attached to the non-AP MLD that is transitioning from active mode to power saving mode or from power saving mode to active mode. In some embodiments, the LI control subfield with the MLPM subtype may include the following: Figure 8B The reserved subfield shown may be implemented as follows Fig.8D The "Cross Link PM Subfield" is shown. Fig.8D In the embodiment, the cross-link PM subfield has a single bit. When the power management mode on the indicated link changes from the active mode to the power saving mode, the cross-link PM subfield may be set to 1. Conversely, when the power management mode on the indicated link changes from the power saving mode to the active mode, the cross-link PM subfield may be set to 0.

[0121] In some embodiments, when the cross-link PM subfield is set to "1", a value of 1 in bit position i of the link ID bitmap of the LI control subfield may indicate to the AP MLD that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is transitioning from an active mode to a power save mode. Similarly, when the cross-link PM subfield is set to "0", a value of 1 in bit position i of the link ID bitmap of the LI control subfield may indicate to the AP MLD that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is transitioning from a power save mode to an active mode. In one embodiment, the bit corresponding to the link in which the LI control subfield with the MLPM subtype is sent may always be set to 0.

[0122] In some embodiments, the non-AP MLD can ensure that the STA indicated to transition from active mode to power saving mode in the LI control subfield with the MLPM subtype immediately transitions to the sleep state after the MLPM delay duration from the transmission of the LI control subfield. Therefore, if the indicated STA receives a downlink frame during the MLPM delay duration, the STA should complete the frame exchange sequence and indicate its power management mode state again using the PM bit within the frame exchange sequence.

[0123] When an AP affiliated with an AP MLD receives a frame including a LI Control subfield with an MLPM subtype from a non-AP MLD, the AP may share information with other APs operating on the links indicated as 1 in the Link ID Bitmap subfield. After receiving the LI Control subfield, these other APs may immediately start buffering traffic or BUs for their respective STAs affiliated with the non-AP MLD operating on their respective links after the duration specified by the MLPM Delay.

[0124] In some embodiments, the non-AP MLD may ensure that a STA indicated to transition from power saving mode to active mode in the LI control subfield with the MLPM subtype transitions to the awake state within the MLPM delay duration from the transmission of the LI control subfield. In another embodiment, the non-AP MLD may ensure that a STA indicated to transition from power saving mode to active mode in the LI control subfield with the MLPM subtype transitions to the awake state before transmitting the LI control subfield.

[0125] When an AP affiliated with an AP MLD receives a frame including a LI Control subfield with a MLPM subtype from a non-AP MLD, the AP may share information with other APs operating on the link indicated as 1 in the Link ID Bitmap subfield. After receiving the LI Control subfield with a MLPP subtype, these other APs may schedule the transmission of buffered BUs or traffic for their respective STAs affiliated with the non-AP MLD operating on their respective links immediately after the duration specified by the MLPM Delay subfield.

[0126] In one embodiment, the LI control subfield with the MLPM subtype may not be transmitted by the AP MLD. However, in another embodiment where the power management mode change is applicable to the AP MLD, the LI control subfield with the MLPM subtype may also be transmitted by the AP MLD.

[0127] In reference Fig.8D In a variation of the illustrated embodiment, bit B3 of the LI Control subfield with the MLPM subtype corresponding to the Cross-Link PM subfield may be reserved. Instead, the Link ID Bitmap subfield, in conjunction with the PM bits of the Frame Control field carried in a frame including the LI Control subfield with the MLPM subtype, may be used to determine whether the MLPM indication is for transitioning from an active mode to a power saving mode indication or vice versa.

[0128] For ease of description, assume that the ID of the link on which a frame including the LI control subfield with the MLPM subtype is transmitted is j. Then, the MLPM indication can be interpreted as follows:

[0129] - If the PM bit in the Frame Control field is set to 1 and the bit corresponding to link ID j in the Link ID Bitmap subfield of the LI Control subfield is set to 1, then the MLPM indication is for transitioning from active mode to power save mode. For example, a value of 1 in bit position I of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is transitioning from active mode to power save mode.

[0130] - If the PM bit in the Frame Control field is set to 1 and the bit corresponding to link ID j in the Link ID Bitmap subfield of the LI A Control subfield is set to 0, then the MLPM indication is for transitioning from power save mode to active mode. For example, a value of 1 in bit position i of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i (except i=j) is transitioning from power save mode to active mode.

[0131] - If the PM bit in the Frame Control field is set to 0 and the bit corresponding to link ID j in the Link ID Bitmap subfield of the LI A Control subfield is set to 1, then the MLPM indication is for transitioning from power save mode to active mode. For example, a value of 1 in bit position i of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is transitioning from power save mode to active mode.

[0132] - If the PM bit in the Frame Control field is set to 0 and the bit corresponding to link ID j in the Link ID Bitmap subfield of the LI A Control subfield is set to 0, then the MLPM indication is for transitioning from active mode to power save mode. For example, a value of 1 in bit position i of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i (except i=j) is transitioning from active mode to power save mode.

[0133] In the above example, an XOR between the PM bit and the bit corresponding to link ID j in the link ID bitmap subfield of the LI control subfield with the MLPM subtype can be used to determine whether the MLPM indication is for transitioning from active mode to power saving mode indication, or vice versa. In this example, all links whose corresponding bits in the link ID bitmap are set to 1, except for link ID j, are determined to be indicated links for power management mode switching. A value of 0 in bit position i of the link ID bitmap can indicate to the AP MLD that the STA affiliated with the non-AP MLD operating on the link with link ID equal to i is not a STA indicated for management mode switching. In this example, the indication of link ID j can be determined based on the PM bit.

[0134] In some embodiments, the bit corresponding to link ID i in the Link ID Bitmap subfield of the LI Control subfield with the MLPM subtype may function in a similar manner to the PM bit for link ID i. In some implementations, a value of 1 in bit position i of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is entering a power save mode. A value of 0 in bit position i of the Link ID Bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is entering an active mode. In these embodiments, this indication does not necessarily imply that the power management mode on the corresponding link is changing.

[0135] As will be explained in further detail below, the cross-link power management indication and / or the cross-link power saving state indication may be sent within a new protected EHT (extremely high throughput) action frame. The new protected EHT action frame may be a single action frame applicable to both indications, and it may be referred to as a "multi-link power management (MLPM) notification frame".

[0136] Fig.9A An example of an MLPM notification frame format according to an embodiment is shown. Fig. 9B An example of a protected EHT Action field value according to an embodiment is shown. Fig. 9C An example of the MLPM Notification field format according to an embodiment is shown. As discussed, in this example, the MLPM Notification frame is a newly defined protected EHT Action frame.

[0137] refer to Fig.9A , the MLPM notification frame may include a category field, a protected EHT action field, and a multi-link power management (MLPM) field. The category field may include a category value for the action frame. The protected EHT action field may distinguish the protected EHT action frame from other frames. Fig. 9B is an example table of protected EHT action field values ​​including an MLPM notification frame according to an embodiment. Fig. 9C Explain the MLPM field in more detail.

[0138] refer to Fig. 9C , the MLPM Notification field may include a Type subfield, a Reserved subfield, and a Link ID Bitmap subfield. In this example, the bit sizes of these subfields may be 2 bits, 6 bits, and 16 bits, respectively. The Type subfield may indicate the type of power management change. Table 3 below shows an example of the definition and encoding of the MLPM Support subfield.

[0139] [Table 3]

[0140]

[0141] The above encoding may indicate whether the purpose of the MLPM notification frame is to indicate a multi-link power management mode change or to indicate a multi-link power saving state change. In some embodiments, the type subfield may have only a single bit to indicate whether it is for power management mode indication (e.g., set to 1) or power saving state indication (e.g., set to 0).

[0142] The link ID bitmap subfield may indicate a link ID for power management mode indication or power saving state indication. In some embodiments, the encoding of the link ID bitmap subfield may be implemented as follows. For example, a value of 1 in bit position i of the link ID bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is associated with a power management mode change or a power saving state change. Conversely, a value of 0 in bit position i of the link ID bitmap subfield may indicate that a STA affiliated with a non-AP MLD operating on a link with link ID equal to i is not associated with a power management mode change or a power saving state change. In some embodiments, the link ID bitmap subfield may be encoded with reference to Figure 8B and Fig.8D In one embodiment, the MLPM notification frame may not be sent by the AP MLD.

[0143] In some embodiments, when the Type subfield is set to 0 or 1, the indication of the link on which the transmitting STA is operating may not contradict the indication in the PM bit of the Frame Control field carrying the MLPM Notification frame.

[0144] In some embodiments, the non-AP MLD may ensure that the STA indicated as 1 in the Link ID Bitmap subfield with the Type subfield set to 1 or 2 transitions to the awake state within the MLPM delay duration from the transmission of the MLPM notification frame. In some embodiments, the non-AP MLD may ensure that the STA indicated as 1 in the Link ID Bitmap subfield with the Type subfield set to 1 or 2 transitions to the awake state before transmitting the MLPM notification frame.

[0145] In some embodiments, after sending the MLPM notification frame, the non-AP MLD may ensure that STAs indicated as 1 in the Link ID Bitmap subfield with the Type subfield set to 0 immediately transition to the sleep state of the power saving mode after the MLPM delay duration.

[0146] When an AP affiliated with an AP MLD receives an MLPM notification frame from a non-AP MLD, the AP may share information with other APs operating on links indicated as 1 in the Link ID Bitmap subfield of the MLPM field. If the Type subfield is set to 0, other APs may start buffering traffic for STAs affiliated with non-AP MLDs operating on the links after a specific time period (e.g., MLPM delay duration) after receiving the MLPM notification frame. If the Type subfield is set to 1, other APs may stop buffering traffic after receiving the MLPM notification frame and may schedule transmission of any buffered traffic for STAs affiliated with non-AP MLDs operating on these links after a specific time period (e.g., MLPM delay duration). If the Type subfield is set to 2, other APs may schedule transmission of any buffered traffic for STAs affiliated with non-AP MLDs operating on the links after a specific time period (e.g., MLPM delay duration) after receiving the MLPM notification frame.

[0147] Fig.10 A flow chart illustrating an example process 1000 for AP MLD according to an embodiment is shown. Although one or more operations are described or shown in a particular sequential order, in other embodiments, the operations may be rearranged in a different order, which may include performing multiple operations in at least partially overlapping time periods.

[0148] Process 1000 may begin with operation 1001. In operation 1001, an AP MLD may indicate to one or more associated non-AP MLDs an ability to receive a cross-link PM mode switch indication and / or a power saving state switch indication.

[0149] In operation 1003, the AP MLD may indicate an inter-AP communication delay of the cross-link signaling (i.e., a cross-link PM mode switching indication and / or a power saving state switching indication) to one or more associated non-AP MLDs, where the inter-AP communication delay may be the amount of time required for the AP MLD to process and successfully apply the cross-link signaling.

[0150] In operation 1005, when the first AP attached to the AP MLD receives a frame indicating a power management mode switch or a power saving state switch for a second STA attached to the non-AP MLD from a first STA attached to the non-AP MLD, the APMLD may parse the information and transmit the parsed information to the second AP attached to the AP MLD. The second AP attached to the AP MLD is associated with the second STA attached to the non-AP MLD. Then, the process 1000 proceeds to operation 1007.

[0151] In operation 1007, the AP MLD may start or stop buffering traffic, or start delivering traffic to a second STA affiliated with the non-AP MLD, based on an indication regarding a power management mode switch or a power saving state switch.

[0152] Fig.11 A flow chart illustrating an example process 1100 for non-AP MLD according to an embodiment is shown. Although one or more operations are described or shown in a particular sequential order, in other embodiments, the operations may be rearranged in a different order, which may include performing multiple operations in at least partially overlapping time periods.

[0153] Process 1100 may start with operation 1101. In operation 1101, the non-AP MLD may receive and check capability information of the AP MLD for receiving a cross-link PM mode switching indication and / or a power saving state switching indication.

[0154] In operation 1103, when there is a power management mode switch for the STA set attached to the non-AP MLD, the non-AP MLD may encode information to indicate the change and send a frame including the power management mode switch indication to the AP attached to the AP MLD. The frame including the power management mode switch indication may be sent to any AP attached to the associated AP MLD.

[0155] In operation 1105, when there is a power saving state switch for the STA set attached to the non-AP MLD, the non-AP MLD may encode information to indicate the change and send a frame including the power saving state switch indication to the AP attached to the AP MLD. The frame including the power saving state switch indication may be sent to any AP attached to the associated AP MLD.

[0156] In operation 1107, the non-AP MLD may ensure that any required rules are followed, taking into account the inter-AP communication delay indicated in the MLPM Delay subfield. For example, the non-AP MLD may ensure that a STA associated with a power management mode switch or a power saving state switch changes its power management mode or power saving state within a specific time period (e.g., MLPM Delay duration) from sending an indication of the power management mode switch or the power saving state switch. In some embodiments, the non-AP MLD may ensure that a STA associated with a power management mode switch or a power saving state switch changes its power management mode or power saving state before sending an indication of the power management mode switch or the power saving state switch.

[0157] Unless otherwise specifically stated, referring to an element in the singular does not mean one and only one, but one or more. For example, "a" module may refer to one or more modules. In the absence of further constraints, an element beginning with "a", "an", "the" or "said" does not exclude the presence of other identical elements.

[0158] Headings and subheadings, if any, are for convenience only and do not limit the invention. The word "exemplary" is used to mean serving as an example or illustration. To the extent that the words "including," "having," and the like are used, such words are intended to be inclusive in a manner similar to how the word "comprising" is interpreted when used as a transitional word in a claim. Relational words such as first and second, and the like may be used to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0159] Phrases such as an aspect, this aspect, another aspect, some aspects, one or more aspects, an embodiment, this embodiment, another embodiment, some embodiments, one or more embodiments, an example, this example, another example, some examples, one or more examples, a configuration, this configuration, another configuration, some configurations, one or more configurations, subject technology, disclosure, the present disclosure, other variations thereof, etc. are for convenience and do not imply that the disclosures associated with these phrases are basic to the subject technology or that these disclosures are applicable to all configurations of the subject technology. The disclosures associated with these phrases may apply to all configurations, or one or more configurations. The disclosures associated with these phrases may provide one or more examples. Phrases such as an aspect or some aspects may refer to one or more aspects, and vice versa, and the same applies to the other aforementioned phrases.

[0160] The phrase "at least one of" preceding a series of items separated by the words "and" or "or" modifies the entire list, rather than each element of the list. The phrase "at least one of" does not require selection of at least one item; rather, the phrase allows for the meaning to include at least one of any one item, and / or at least one of any combination of items, and / or at least one of each item. For example, each of the phrases "at least one of A, B, and C" or "at least one of A, B, or C" means: only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

[0161] It should be understood that the steps, operations or processes of the specific order or hierarchy disclosed are illustrations of exemplary methods. Unless otherwise expressly stated, it should be understood that the steps, operations or processes of the specific order or hierarchy may be performed in a different order. Some of the steps, operations or processes may be performed simultaneously or as part of one or more other steps, operations or processes. The accompanying method claims (if any) present the elements of the various steps, operations or processes in a sample order and are not meant to be limited to the specific order or hierarchy presented. These may be performed serially, linearly, in parallel or in a different order. It should be understood that the instructions, operations and systems described may generally be integrated together in a single software / hardware product or packaged into multiple software / hardware products.

[0162] The present disclosure is intended to enable any person skilled in the art to practice the various aspects described herein. In some cases, in order to avoid blurring the concept of the subject technology, well-known structures and components are shown in block diagram form. The present disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. It will be easy for those skilled in the art to understand various modifications to these aspects, and the principles described herein can be applied to other aspects.

[0163] All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element shall be interpreted under the provisions of 35 USC §112, sixth paragraph, unless the element is clearly recited using the phrase "means for..." or, in the case of a method claim, the element is recited using the phrase "step."

[0164] The “Title,” “Background,” “Brief Description of the Figures,” “Abstract,” and “Drawings” are hereby incorporated into the present disclosure and are provided as illustrative examples of the present disclosure, rather than as limiting descriptions. They are submitted with the understanding that they will not be used to limit the scope or meaning of the claims. Further, in the detailed description, it can be seen that the description provides illustrative examples and that various features are grouped together in various embodiments for the purpose of simplifying the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the inventive subject matter lies in less than all the features of a single disclosed configuration or operation. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separately claimed subject matter.

[0165] The claims are not intended to be limited to the aspects described herein, but are to be accorded the full scope consistent with the language of the claims and to encompass all legal equivalents. Nevertheless, no claims are intended to encompass subject matter that fails to satisfy the requirements of applicable patent law, nor should they be interpreted in such a manner.

Claims

1. A non-AP MLD associated with an access point (AP) multi-link device (MLD) in a wireless network, the non-AP MLD comprising: at least two stations (STAs), each STA being attached to the non-AP MLD; as well as at least one processor, the at least one processor being coupled to the at least two STAs, the at least one processor being configured to: determining a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD; as well as A frame is sent to a first AP attached to the AP MLD over a first link established between a first STA attached to the non-AP MLD and the first AP attached to the AP MLD, the frame including a field indicating a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD.

2. The non-AP MLD according to claim 1, wherein the field includes a first subfield and a second subfield, the first subfield indicating whether the field includes a power management mode change indication or a power saving state change indication, and the second subfield indicating one or more links of the AP MLD associated with the power management mode change or the power saving state change.

3. The non-AP MLD of claim 1 , wherein the power management mode change is a change from an active mode to a power saving mode or a change from a power saving mode to an active mode, and the power saving state change is a change from a sleep state to an awake state or a change from an awake state to a sleep state.

4. The non-AP MLD according to claim 2, wherein the frame includes a third subfield indicating whether the power management mode is transitioned from the active mode to the power saving mode or from the power saving mode to the active mode, and Wherein the power management mode change is determined based on the first subfield and the third subfield.

5. The non-AP MLD of claim 1 , wherein the at least one processor is further configured to: participate in a frame exchange with at least one AP attached to the AP MLD on each link between the non-AP MLD and the APMLD if the field indicates that the one or more STAs transition to an active mode or awake state, and The at least one AP is associated with at least one STA among the one or more STAs.

6. The non-AP MLD according to claim 1, wherein the at least one processor is further configured to receive capability information from the APMLD, the capability information indicating whether the AP MLD supports receiving a power management mode change indication or a power saving state change indication for one or more STAs attached to the non-AP MLD.

7. The non-AP MLD of claim 1 , wherein the at least one processor is further configured to: receiving processing delay information indicating an amount of time to process a power management mode change indication or a power saving state change indication, and A power management mode change or a power saving state change for the one or more STAs is performed at a time determined based on the amount of time indicated by the processing delay information.

8. An AP multi-link device (MLD) associated with a non-access point (AP) in a wireless network, the AP MLD comprising: at least two APs, each AP being attached to the AP MLD; as well as at least one processor, the at least one processor being coupled to the at least two APs, the at least one processor being configured to: receiving a frame from a first STA attached to the non-AP MLD on a first link established between the first STA and a first AP attached to the AP MLD, the frame including a field indicating a power management mode change or a power saving state change for one or more STAs attached to the non-AP MLD; In response to determining that the one or more STAs transition to an active mode or awake state based on the field included in the frame, initiating a frame exchange with at least one of the one or more STAs on each link between the AP MLD and the non-AP MLD; as well as In response to determining that the one or more STAs transition to a sleep state based on the field included in the frame, buffering of a bufferable unit of at least one of the one or more STAs is initiated.

9. The AP MLD according to claim 8, wherein the field includes a first subfield and a second subfield, the first subfield indicating whether the field includes a power management mode change indication or a power saving state change indication, and the second subfield indicating one or more links of the AP MLD associated with the power management mode change or the power saving state change.

10. The AP MLD of claim 8, wherein the power management mode change is a change from an active mode to a power saving mode or a change from a power saving mode to an active mode, and the power saving state change is a change from a sleep state to an awake state or a change from an awake state to a sleep state.

11. The AP MLD according to claim 9, wherein the frame comprises a third subfield indicating whether the power management mode is transitioned from an active mode to a power saving mode or from a power saving mode to an active mode, and in, The at least one processor is configured to determine the power management mode change based on the first subfield and the third subfield.

12. The AP MLD according to claim 8, wherein the at least one processor is further configured to send capability information to the non-AP MLD, the capability information indicating whether the AP MLD supports receiving a power management mode change indication or a power saving state change indication for one or more STAs attached to the non-AP MLD.

13. The AP MLD of claim 8, wherein the at least one processor is further configured to: sending processing delay information indicating an amount of time to process a power management mode change indication or a power saving state change indication, and At a time determined based on the processing delay information, a frame exchange with at least one of the one or more STAs is initiated or buffering of a bufferable unit of at least one of the one or more STAs is initiated.

14. A method performed by an access point (AP) multi-link device (MLD) associated with a non-AP MLD in a wireless network, the method comprising operations performed by at least one processor in the non-AP MLD according to one of claims 1 to 7.

15. A method performed by an access point (AP) multi-link device (MLD) associated with a non-AP MLD in a wireless network, the method comprising operations performed by at least one processor in the AP MLD according to one of claims 8 to 13.

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