Wake-up time recommendation for access points

Abstract

Methods and apparatus are provided that enable an AP MLD to indicate to one or more non-AP MLDs their recommended wake-up times on one or more links. In some embodiments, the recommended wake-up time may be continued for at least one STA over a prescribed number of intervals. Features are also provided for the STA to request wake-up time recommendations from the AP as well as rules that the STA adheres to. In one aspect of the present disclosure, an AP transmits a wakeup time recommendation element (WTRE) in a beacon interval. The WTRE includes a recommendation to recommend one, multiple, or all stations to postpone their wake-up time to a recommended wake-up time, rather than an immediate wake-up time.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to wireless communication, and more specifically to wake-up time in wireless local area network (WLAN) technology, for example, but not limited to. BACKGROUND

[0002] Wireless local area network (WLAN) technology has evolved towards increased data rates and has continued to grow in various markets such as home, enterprise, and hotspots since the late 1990s. WLAN allows devices to access the Internet in 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz bands. WLAN is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. The IEEE 802.11 family of standards aims to improve speed and reliability and extend the operating range of wireless networks.

[0003] WLAN devices are increasingly required to support various delay-sensitive applications or real-time applications, such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and self-driving vehicles. In order to achieve the extremely low latency and extremely high throughput required for such applications, multi-link operation (MLO) has been developed for WLAN. A WLAN is formed by WLAN devices within a limited area such as a home, school, apartment, or office building. Each WLAN device can have one or more stations (STAs), such as an access point (AP) STA and a 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. However, current solutions for traffic indication, data acquisition, and premature wake-up can result in significantly high power consumption, which in turn causes overall performance degradation.

[0005] The description set forth in the Background section is not an admission that any of the SUMMARY

[0006] In one aspect of the disclosure, an access point (AP) is provided. The AP includes a memory and a processor coupled to the memory. The processor is configured to transmit a wake-up time recommendation element (WTRE) to one or more stations. The WTRE includes at least (i) an identification of the one or more stations; and (ii) a recommended wake-up time for the one or more stations to start transmitting or receiving data at a wake-up time after the WTRU transmits. The processor is further configured to receive, at the recommended wake-up time, an indication from the one or more stations that the one or more stations are ready to exchange data with the AP.

[0007] In various aspects, the recommended wake-up time is determined based on at least one of a time synchronization function corresponding to the intended wake-up time, one or more transmission elements corresponding to a time gap between the transmission of the WTRE and the intended wake-up time, or an identifier of a beacon segment corresponding to the intended wake-up time, wherein the beacon interval following the transmission of the WTRE is divided into equal-length beacon segments.

[0008] In one embodiment, the WTRE includes an indication of whether the recommended wake-up time is for transmission of: downlink traffic from an AP to one or more stations; uplink traffic from the one or more stations to the AP; or bi-directional traffic for the one or more stations.

[0009] In one embodiment, the WTRE includes an indication of whether the recommended wake-up time is for AP-initiated or triggered transmissions.

[0010] In one embodiment, the WTRE includes an indication of whether at least one recommended wake-up time is optional or mandatory, and a purpose of the recommended wake-up time.

[0011] In one embodiment, the AP is an AP multi-link device (MLD) including one or more affiliated APs, and the AP MLD establishes one or more links, each associated with a respective one of the one or more affiliated APs. During multi-link operation (MLO), the WTRE is configured to indicate one or more links for which the WTRE is valid.

[0012] In one embodiment, the WTRE includes a plurality of stations assigned to a same recommended wake-up time or an order number in stations assigned a same recommended wake-up time.

[0013] In one embodiment, the WTRE includes an indication of whether the recommendation is a long-term recommendation for at least one station to continue for a specified period of time.

[0014] In another aspect of the disclosure, a station in a wireless network is provided. The station includes a memory and a processor coupled to the memory. The processor is configured to send a request to an access point (AP) to issue a wake-up time recommendation element (WTRE). The processor is further configured to receive the WTRU from the AP, the WTRE including at least (i) an identification of one or more stations; and (ii) a recommended wake-up time for the one or more stations to start transmitting or receiving data at the recommended wake-up time following the transmission of the WTRE. The processor is further configured to wake up at the recommended time and transmit an indication that the station is ready to exchange data with the AP at the recommended time.

[0015] In one embodiment, the processor is further configured to, in case of an impending collision or a collision between transmissions, follow a back-off procedure identified by the AP; and reinitiate transmission at a designated time after completion of the back-off procedure to acquire traffic from the AP.

[0016] In one embodiment, the processor is further configured to receive a trigger frame from the AP requesting the station to send a power save (PS) poll frame at a recommended wake-up time, and send the PS poll frame to the AP at the recommended wake-up time.

[0017] In one embodiment, the one or more stations comprise non-AP stations.

[0018] In one embodiment, the WTRE includes an indication of a duration for which the recommended wake-up time is to remain valid. The station is configured to wake up at the recommended wake-up time to perform frame exchange with the AP.

[0019] In one embodiment, the station is a non-AP multi-link device (MLD) comprising one or more affiliated non-AP stations, and the non-AP MLD establishes one or more links, each link being associated with a respective one of the one or more affiliated non-AP stations. During multi-link operation (MLO), the one or more affiliated non-AP stations transition to an awake state at a recommended wake-up time on a recommended link, the recommended link being indicated by a link identifier included in the WTRE.

[0020] In one embodiment, the WTRE includes an indication as to whether the recommendation is a long-term recommendation for the at least one station to persist for a specified period of time.

[0021] In yet another aspect of the disclosure, a method performed by an access point (AP) includes sending a wake-up time recommendation element (WTRE) to one or more stations. The WTRE includes at least (i) an identification of the one or more stations; and (ii) a recommended wake-up time for the one or more stations to start sending or receiving data at the wake-up time after sending the WTRU. The method further includes receiving, from the one or more stations at the recommended wake-up time, an indication that the one or more stations are ready to exchange data with the AP.

[0022] In one embodiment, the WTRE includes an indication of a duration for which the recommended wake-up time is to remain valid. The WTRE includes an indication as to whether compliance with the at least one recommended wake-up time is optional or mandatory, and a purpose of the recommended wake-up time.

[0023] In one embodiment, the processor is further configured to determine a recommended wake-up time based on at least one of the following: a time synchronization function corresponding to the expected wake-up time, one or more transmission units corresponding to the time gap between the transmission of the WTRF and the expected wake-up time, or an identifier of a beacon segment corresponding to the expected wake-up time, wherein the beacon interval after the transmission of the WTRF is divided into beacon segments of equal length.

[0024] In one embodiment, the WTRE includes an indication of whether the recommendation is a long-term recommendation that is continuously used for at least one station over a specified period of time. Attached Figure Description

[0025] Figure 1 An example of a wireless network according to an embodiment is shown.

[0026] Figure 2a An example of an AP according to an embodiment is shown.

[0027] Figure 2b An example of a STA according to an embodiment is shown.

[0028] Figure 3 An example of multi-link communication operation according to an embodiment is shown.

[0029] Figure 4 An example timing diagram of the current AP / beacon acquisition for the service is shown.

[0030] Figure 5a An example of a timing diagram of an AP beacon signal including a wake-up time recommendation element (WTRE) according to an embodiment is shown.

[0031] Figure 5b An example of a timing diagram with multiple beacons and a signaling field including information about the WTRE is shown according to an embodiment.

[0032] Figure 6 An illustration of an embodiment for use Figure 5a Example beacon interval (BI) segment assignment list field for WTRE.

[0033] Figure 7 An example is shown of using a Multi-User Request Transmission (MU-RTS) trigger frame as the standard for wake-up recommendation, according to an embodiment.

[0034] Figure 8a An example is shown whereby WTRE, according to an embodiment, provides a BI segment indication of multiple links by indicating the size of the link set.

[0035] Figure 8b An example is shown whereby WTRE provides BI segment indications for multiple links by setting a link ID bitmap, according to an embodiment.

[0036] Figure 9 An example of a traffic indication virtual bitmap and its mapping to a list of BI segment allocations in a WTRE is shown, according to an embodiment.

[0037] Figure 10a A WTRE with an associated identifier (AID) bitmap element to identify all AIDs for which the wake-up time indication applies is shown.

[0038] Figure 10b A WTRE using a wake-up time field indicating the time at which the AP indicates the STA to wake up, according to an embodiment, is shown.

[0039] Figure 11 A timing diagram showing that an AP can segment a beacon into different segments and can optionally trigger a frame by indicating a random access resource unit (RA-RU) in a WTRE, according to an embodiment, is shown.

[0040] Figure 12 An "extended" recommendation by an AP of a WTRE to indicate to a STA the time at which the AP intends to serve the STA with a buffer unit (BU) it can have, according to an embodiment, is shown.

[0041] Figure 13 An embodiment in which an AP can send a WTRE to a STA in a separately addressed frame to indicate that it has a BU for the STA, including the case of multiple times using multiple links, according to an embodiment, is shown.

[0042] Figure 14 An example timing diagram in which a STA can negotiate with an AT to provide an additional wake-up delay for addition to a recommended wake-up time, according to an embodiment, is shown.

[0043] Figure 15 An example flow diagram of a process for recommending a wake-up time by an AP, according to an embodiment, is shown.

[0044] Figure 16 Another example flow diagram of a process for receiving a WTRE by a STA from an AP and for waking up at a specified time to get a BU, according to an embodiment, is shown.

[0045] Figure 17 A timing diagram showing an alternative embodiment in which an AP uses a WTRE to apply within a particular service period (SP) rather than the entire beacon interval, according to an embodiment, is shown.

[0046] In one or more embodiments, not all of the components depicted in the figures are required, and one or more embodiments can include additional components not shown in the figures. Variations to the arrangements and types of components can be made without departing from the scope of the subject disclosure. Additional components, different components, or fewer components can be utilized within the scope of the subject disclosure. DETAILED DESCRIPTION

[0047] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various implementations and is not intended to represent the only implementations in which the subject technology can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the inventive concepts. As one skilled in the art will appreciate, the described implementations can be practiced with variations of the implementations not described herein, without departing from the scope of the disclosure. Accordingly, the disclosure is not limited to the specific implementations described in this detailed description. Rather, the detailed description is intended to provide a thorough understanding of the subject technology.

[0048] For the purpose of describing the innovative aspects of the present disclosure, the following description focuses on certain implementations. However, one skilled in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The examples in this disclosure are based on WLAN communications according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, including the IEEE 802.11be standard and any future revisions to the IEEE 802.11 standards. However, the described embodiments can be implemented in any device, system, or network capable of sending and receiving radio frequency (RF) signals according to the IEEE 802.11 standards, the Bluetooth standard, 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), lxEV-DO, EV-DO Rev A, EV-DO Rev R, 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, or other known signals that are used in wireless, cellular, or Internet of Things (IoT) networks (such as systems utilizing 3G, 4G, 5G, 6G, or further implementations thereof).

[0049] The following terms, unless otherwise indicated, apply to the disclosure. The term “coupled” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” and derivatives thereof, encompass both direct and indirect communication. The phrase “associated with,” and derivatives thereof, means includes, is included in, interconnects with, contains, is contained within, connects to or with, couples to or with, is communicable with, cooperates with, interleases, is proximate to, is bound to or with, has, has a property of, has a relationship to or with, and the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase “at least one of” when used with a list of items means that a different combination of one or more of the listed items can be utilized and that only one item from the list can be needed. For example, “at least one of A, B, or C” includes any one or any combination of the following: A, B, C, A and B, A and C, B and C, and A and B and C.

[0050] Furthermore, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or portions thereof applicable for implementation by a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links. Non-transitory computer readable media include media where data is permanently stored and media where data is stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

[0051] Figure 1 An example of a wireless network 100, in accordance with embodiments, is shown. Figure 1 The illustrated embodiment of the wireless network 100 is for purposes of illustration and explanation only. Other embodiments of the wireless network 100 can be used without departing from the scope of the disclosure.

[0052] like Figure 1 As shown, wireless network 100 includes multiple wireless communication devices. Each wireless communication device may include one or more stations (STAs). An STA can be a logical entity, which is a separately addressable instance of the Media Access Control (MAC) layer and Physical (PHY) layer interface to the wireless media. STAs can be classified as Access Point (AP) STAs and Non-Access Point (Non-AP) STAs. An AP STA can be an entity that provides access to distributed system services to associated STAs via the wireless media. A Non-AP STA can be a STA that is not included in an AP-STA. For simplicity, an AP STA may be referred to as an AP, and a Non-AP STA may be referred to as a STA. Figure 1 In the example, APs 101 and 103 are wireless communication devices, and each wireless communication device may include one or more AP STAs. In such an embodiment, APs 101 and 103 may be AP multilink devices (MLDs). As mentioned earlier, traditional standards support multi-band operation, enabling APs and non-AP STAs to communicate with each other through multiple links. Therefore, both APs and non-AP STAs can communicate on different frequency bands / links, which is referred to herein as multilink operation (MLO). Devices capable of performing MLO are called multilink devices (MLDs). STAs 111-114 are wireless communication devices, and each wireless communication device may include one or more non-AP STAs. In such an embodiment, STAs 111-114 may be non-AP MLDs.

[0053] 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 to multiple stations (STAs) 111-114 in the coverage area 120 of AP 101. APs 101 and 103 can communicate with each other and with STAs using Wi-Fi or other WLAN communication technologies.

[0054] Depending on the network type, other well-known terms can be used instead of "access point" or "AP," such as "router" or "gateway." For the sake of convenience, the term "AP" is used in this disclosure to refer to network infrastructure components that provide wireless access to remote terminals. In WLANs, an AP can also be referred to as a STA assuming the AP also contends for the wireless channel. Also, depending on the network type, other well-known terms can be used instead of "station" or "STA," such as "mobile station," "subscriber station," "remote terminal," "user device," "wireless terminal," or "user equipment." For the sake of convenience, the terms "station" and "STA" are used in this disclosure to refer to remote wireless equipment that wirelessly accesses an AP or contends for the wireless channel in WLANs, whether the STA is a mobile device such as a mobile telephone or smartphone, or is typically considered a fixed device such as a desktop computer, an AP, a media player, a fixed sensor, a television, etc.

[0055] In Figure 1 , dashed lines show the approximate extents of the coverage areas 120 and 125 of the APs 101 and 103, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with APs, such as the coverage areas 120 and 125, can have other shapes, including irregular shapes, depending on the configuration of the APs.

[0056] As described in more detail below, one or more of the APs can include circuitry and / or programming for managing MU-MIMO and OFDMA channel sounding in the WLAN. Although Figure 1 one example of a wireless network 100 is shown, various changes can be made to Figure 1 the wireless network 100. For example, the wireless network 100 could include any number of APs and any number of STAs in any suitable arrangement. In addition, the AP 101 could communicate directly with any number of STAs and provide those STAs with wireless broadband access to the network 130. Similarly, each AP 101 and 103 could communicate directly with the network 130 and provide STAs with direct wireless broadband access to the network 130. Further, the APs 101 and / or 103 could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0057] Figure 2a An example of an AP 101 according to an embodiment is shown. Figure 2a The illustrated embodiment of the AP 101 is for illustration only, and Figure 1 The AP 103 can have the same or a similar configuration. However, APs have a wide variety of configurations, and Figure 2a the scope of this disclosure is not limited to any particular implementation of an AP.

[0058] like Figure 2a As shown, AP 101 includes multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. AP 101 also includes a controller / processor 224, a memory 229, and a backhaul or network interface 234. RF transceivers 209a-209n receive incoming RF signals from antennas 204a-204n, such as signals transmitted by STAs in network 100. RF transceivers 209a-209n down-convert the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are sent to RX processing circuitry 219, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 219 sends the processed baseband signals to controller / processor 224 for further processing.

[0059] TX processing circuit 214 receives analog or digital data (such as voice data, web data, email, or interactive video game data) from controller / processor 224. TX processing circuit 214 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 209a-209n receive the processed baseband or IF signal from TX processing circuit 214 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 204a-204n.

[0060] The controller / processor 224 can include one or more processors or other processing devices to manage the overall operation of the AP 101. For example, the controller / processor 224 can control the reception of downlink signals and the transmission of uplink signals by the RF transceivers 209a-209n, the RX processing circuitry 219, and the TX processing circuitry 214 in accordance with well-known principles. The controller / processor 224 can support additional functions as well, such as more sophisticated wireless communication functions. For instance, the controller / processor 224 can support beam forming or directional routing operations in which outgoing signals from different antennas 204a-204n are weighted differently to effectively steer the outgoing signals in a desired direction. The controller / processor 224 can also support OFDMA operations in which outgoing signals are assigned to different subcarrier subsets of the available subcarriers for the different recipient STAs 111-114. In the AP 101, the controller / processor 224 can support any of a number of additional functions as well, including combining DL MU-MIMO and OFDMA in the same transmission opportunity. In some embodiments, the controller / processor 224 includes at least one microprocessor or microcontroller. The controller / processor 224 can also be capable of executing software or other processes resident in the memory 229, such as an OS. The controller / processor 224 can move data into or out of memory 229 as needed for execution of processes.

[0061] 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. It will be appreciated that the interface 234 could mediate

[0062] As described in more detail below, the AP 101 can include circuitry and / or programming for managing channel sounding procedures in a WLAN. Although Figure 2a One example of an AP 101 is shown, but various changes can be made Figure 2a For example, the AP 101 could include any number of Figure 2aEach of the components shown. As a particular example, the AP can include multiple instances of the interface 234, and the controller / processor 224 can support routing functions to route data between different network addresses. As another example, while shown as including a single instance of TX processing circuitry 214 and a single instance of RX processing circuitry 219, the AP 101 can include multiple instances of each component, such as one per RF transceiver. Alternatively, such as in a traditional AP, only one antenna and one RF transceiver path can be included. Further, Figure 2a The various components in the

[0063] As Figure 2a shown, in some embodiments, the AP 101 can be an AP MLD that includes multiple APs 202a-202n. Each AP 202a-202n is affiliated with the AP MLD 101 and includes multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. Each AP 202a-202n can independently communicate with the controller / processor 224 and other components of the AP MLD 101. Figure 2a Each AP 202a-202n is shown as having separate multiple antennas, but the multiple antennas 204a-204n can be shared by each AP 202a-202n without requiring separate multiple antennas. Each AP 202a-202n can represent a physical (PHY) layer and lower media access control (MAC) layer.

[0064] Figure 2b An example of a STA 111 according to an embodiment is shown. Figure 2b The embodiments of the STA 111 shown are for illustration purposes and Figure 1 The STAs 111-114 can have the same or similar configuration. However, STAs have a wide variety of configurations and Figure 2b The scope of the disclosure is not limited to any particular implementation of a STA.

[0065] As Figure 2b shown, the STA 111 includes an antenna 205, an RF transceiver 210, TX processing circuitry 215, a microphone 220, and RX processing circuitry 225. The STA 111 also includes a speaker 230, a controller / processor 240, an input / output (I / O) interface (IF) 245, a touchscreen 250, a display 255, and a memory 260. The memory 260 includes an operating system (OS) 261 and one or more applications 262.

[0066] The RF transceiver 210 receives, from the antenna 205, an incoming RF signal transmitted by an AP of the network 100. The RF transceiver 210 down-converts the incoming RF signal to generate an IF or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 225, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry 225 transmits 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).

[0067] The TX processing circuitry 215 receives analog or digital voice data from the microphone 220 or other outgoing baseband data (such as web data, e-mail, or interactive electronic game data) from the controller / processor 240. The TX processing circuitry 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 circuitry 215 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna 205.

[0068] The controller / processor 240 can 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 by the RF transceiver 210, the RX processing circuitry 225, and the TX processing circuitry 215 in accordance with well-known principles. The controller / processor 240 can also include processing circuitry configured to provide management of channel sounding procedures in a WLAN. In some embodiments, the controller / processor 240 includes at least one microprocessor or microcontroller.

[0069] 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 procedures in a WLAN. The controller / processor 240 can move data into or out of memory 260 as required by the processes executing on the controller / processor 240. In some embodiments, the controller / processor 240 is configured to execute a plurality of applications 262, such as an application for channel sounding including feedback computation based on received null data packet announcements (NDPAs) and null data packets (NDPs), and sending beamforming feedback reports in response to trigger frames (TFs). The controller / processor 240 can operate the plurality of applications 262 based on the OS program 261 or in response to signals received from the AP. The controller / processor 240 is further coupled to the I / O interface 245, which provides the STA 111 with the ability to connect to other devices such as laptop computers and handheld computers. The I / O interface 245 is the communication path between these accessories and the host controller / processor 240.

[0070] The controller / processor 240 is also connected to the touchscreen 250 and the display 255. The 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, light emitting diode display, or other display capable of rendering text and / or at least limited graphics, such as from web sites. The memory 260 is coupled to the controller / processor 240. Part of the memory 260 can include random access memory (RAM), and another part of the memory 260 can include a flash memory or other read-only memory (ROM).

[0071] Although Figure 2b various changes can be made to Figure 2b the example of the STA 111. For example, Figure 2b various components in the STA 111 can be combined, further subdivided, or omitted and additional components can be added according to particular needs. In a particular example, the STA 111 can include any number of antennas 205 for MIMO communication with the AP 101. In another example, the STA 111 can not include voice communication, or the controller / processor 240 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Also, although Figure 2b the STA 111 is shown as being configured as a mobile telephone or smartphone, the STA can be configured to operate as other types of mobile or stationary devices.

[0072] As Figure 2bAs shown, in some embodiments, the STA 111 can be a non-AP MLD that includes multiple STAs 203a-203n. Each STA 203a-203n is affiliated with the non-AP MLD 111 and includes an antenna 205, an RF transceiver 210, TX processing circuitry 215, and RX processing circuitry 225. Each STA 203a-203n can independently communicate with the controller / processor 240 and other components of the non-AP MLD 111. Figure 2b Each STA 203a-203n is shown as having a separate antenna, but each STA 203a-203n can share the antenna 205 without requiring a separate antenna. Each STA 203a-203n can represent a physical (PHY) layer and lower media access control (MAC) layers.

[0073] Figure 3 An example of MLD communication operations 300 is shown in accordance with an embodiment. The multi-link communication operations can be used for the IEEE 802.11be standard and any future revisions to the IEEE 802.11 standard. In Figure 3 the AP MLD 310 can be one of the wireless communication devices 101 and 103 in Figure 1 the non-AP MLD 220 can be one of the wireless communication devices 111-114 in Figure 1

[0074] As shown in Figure 3 the AP MLD 310 can include multiple affiliated APs, for example, including AP 1, AP 2, and AP 3. Each affiliated AP includes a PHY interface to the wireless medium (link 1, link 2, or link 3). The AP MLD 310 includes a single MAC service access point (SAP) 318 through which the affiliated APs of the AP MLD 310 communicate with higher layers (layer 3 or network layer). Each affiliated AP of the AP MLD 310 can have a MAC address (lower MAC address) that is different from any other affiliated AP of the AP MLD 310. The AP MLD 310 can have an MLD MAC address (upper MAC address), and the affiliated APs share a single MAC SAP 318 to layer 3. Thus, the affiliated APs share a single IP address, and layer 3 identifies the AP MLD 310 by assigning the single IP address.

[0075] ​The non-AP MLD 320 can include multiple affiliated STAs, e.g., including STA 1, STA 2, and STA 3. Each affiliated STA includes a PHY interface to the wireless medium (link 1, link 2, or link 3). The non-AP MLD 320 includes a single MAC SAP 328 through which the affiliated STAs of the non-AP MLD 320 communicate with higher layers (layer 3 or network layer). Each affiliated STA of the non-AP MLD 320 can have a MAC address (lower layer MAC address) that is different from any other affiliated STA of the non-AP MLD 320. The non-AP MLD 320 can have an MLD MAC address (upper layer MAC address), and the affiliated STAs share a single MAC SAP 328 to layer 3. Thus, the affiliated STAs share a single IP address, and layer 3 identifies the non-AP MLD 320 by assigning the single IP address.

[0076] 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 that operates in the 2.4 GHz band. Similarly, AP 2 and STA 2 can establish link 2 that operates in the 5 GHz band, and AP 3 and STA 3 can establish link 3 that operates 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.

[0077] To prioritize the transmission of different types of traffic identified by a traffic identifier (TID) across established links, the non-AP MLD 320 can negotiate a TID-to-link mapping with the AP MLD 310. The TID-to-link mapping allows the AP MLD 310 and the non-AP MLD 320 to determine, respectively, how to allocate frames belonging to a TID for transmission on each established link in the uplink and downlink directions. When at least one TID associated with the non-AP MLD 320 is mapped to an established link in the uplink or 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 this mapping is referred to as the default TID-to-link mapping. During association, the non-AP MLD 320 can 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 re-association request frame. The non-default mapping can be one in which all TIDs are mapped to the same subset of established links, or one in which not all TIDs are mapped to the same subset of established links. The AP MLD 310 can 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 in the downlink and uplink, and all established links are enabled. The non-AP MLD 320 operates in the default mapping mode when TID-to-link mapping negotiation does not occur or is unsuccessful.

[0078] The following documents and standards descriptions are incorporated by reference into the disclosure herein as if fully set forth herein: (1) IEEE 802.11-2020, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification” (2) IEEE 802.11ax; and (3) IEEE P802.11be / D3.0.

[0079] For the purposes of the present disclosure, a WiFi station (STA) can be in one of two states: (1) an awake state, in which the STA continuously monitors the channel and can transmit or receive packets; and (2) a sleep state, in which the STA does not monitor the channel. Examples of (2) include instances where the STA is conserving power. In addition, a non-AP STA can be in one of two power management states: (1) an active mode, in which the STA receives and transmits frames at any time. In this mode, the STA remains in the above-referenced awake state. The second state of a non-AP STA is (2) a power save (PS) mode, in which the STA enters the awake state to receive or transmit frames. Except for instances in which it enters the awake state to exchange frames, a STA in PS mode remains in the sleep state.

[0080] The current version of the technology includes various mechanisms for conserving power. For example, when a STA is in PS mode and the state of the STA is in the sleep state, the corresponding AP buffers packets addressed to the STA that cannot be delivered to another STA associated with the same device in the active state. When the sleeping STA returns to the awake state, these buffered packets (also referred to herein as “buffered units” (BUs)) are delivered by the AP. The AP periodically indicates the BUs pending processing to all associated non-AP devices using broadcast or multicast signaling including a traffic information map (TIM). The AP can also optionally include multi-link traffic indication elements within its transmitted beacon frames. Each AP in a WiFi network can also transmit these elements as separate periodic broadcast frames. The AP can assign a unique association identifier (AID) to each STA to identify the stations the AP is processing. A STA associated with the AP and changing its power management mode notifies the AP of this fact using the power management subfield within the frame control field of the transmitted frames. In the current solution, only frames including an ACK can be used. The subfield “PM” can be set to ‘1’ to indicate power save mode. In addition, power save mechanisms that can be used by non-AP MLDs are currently defined in the above-referenced specifications (1)-(3). These include normal power save mode, unscheduled automatic power save delivery (U-APSD), wireless network management (WNM) power save mode, power save multi-poll mode, spatial reuse power save mode, very high throughput (VHT) TXOP power save (where “TXOP” indicates the amount of time a STA can transmit without having to contend for the medium), target wake time (TWT), etc. In addition, the specifications provide certain features to enable non-AP devices to determine when to be in the “sleep” state versus the “awake” state.

[0081] For example, in order to indicate to STAs when they should transition to the awake state, the specification of IEEE 802.11 ax at the reference (2) cited above also provides the AP with several methods. In one such method, the AP can indicate the start time of one or more broadcast TWT service periods (SPs) with a random access resource unit (RA-RU) included in a broadcast TWT element in a management frame. A "TWT SP with RA-RU" is defined as a TWT SP corresponding to the broadcast TWT parameter set field in a TWT element with a broadcast TWT ID subfield equal to 0 (meaning that all STAs are members), a stream type subfield equal to 0, a trigger subfield equal to 1, and a broadcast TWT recommendation subfield equal to 2. An associated STA that supports TWT and uplink orthogonal random access (UORA) procedures while operating in PS mode, upon receiving a beacon frame carrying a TWT element from its associated AP (the TWT element indicates scheduling for a TWT SP with RA-RU), can enter the sleep state if no other conditions require it to remain awake. The STA can transition to the awake state at the start of the TWT SP with RA-RU to transmit a trigger-based PLCP protocol data unit (PPDU) to its associated AP.

[0082] In another method, the AP can use an aperiodic opportunistic power save (Opportunistic Power Save, OPS). In this technique, an AP with OPS capability transmits an OPS frame or a fast initial link setup (Fast Initial Link Setup, FILS) frame with a broadcast reception address (RA) in order to provide scheduling information for all STAs with OPS capability. The procedure is accomplished by including an OPS element that identifies an OPS period immediately following the OPS frame or the FILS frame, and a TIM element that identifies the AIDs of the STAs that will be served in that period. If the AP with OPS capability sets the bits corresponding to the OPS non-AP STAs in the service indication virtual bitmap field of the TIM element of the OPS frame or the FILS discovery frame to 0, the AP should neither transmit individually addressed frames to that STA nor transmit trigger frames with a user information field addressing that STA during the OPS period immediately following the OPS frame. Such a STA can enter sleep (if in power save mode) or be unavailable (if in active mode).

[0083] In another method described in the IEEE 802.11 ax specification, the AP can use periodic OPS in which the OPS-capable AP divides the beacon interval into several bTWT SPs and provides scheduling information for all OPS-capable STAs at the beginning of each SP. The bTWT recommendation field is set to 3 and the bTWT ID is set to 0 (i.e., everyone is a member STA). At the beginning of the SP, the AP sends a TIM frame or a FILS discovery frame with broadcast RA and including a TIM element and an OPS element. If the OPS-capable AP sets the bits corresponding to the OPS non-AP STAs in the traffic indication virtual bitmap field of the TIM element of the OPS frame or the FILS discovery frame to 0, the AP should neither send individually addressed frames to the STAs nor send trigger frames with user info field addressing the STAs during the OPS period. Such STAs can go to sleep (if in power save mode) or become unavailable (if in active mode).

[0084] An example of “multi-link traffic element construction” is shown in Figure 35-11 in the IEEE 802.11 ax specification cited above. For non-APs in power save mode, the AP can use the traffic information map (TIM) element in the beacon frame to indicate the presence of traffic. Typically, only the TIM element is included. However, if at least one non-AP MLD has a non-default TID-to-link mapping and includes pending data traffic, the ML traffic indication (MLTI) can be added. One bit in the partial virtual bitmap of the TIM element indicates the presence of traffic for an AID (e.g., STA or MLD). The TID-to-link mapping mechanism allows the determination of how a TID (traffic identifier) is mapped to links in the downlink (DL) and uplink (UL), also known as the TID-to-link mechanism. This mechanism helps to use preferred links for TIDs corresponding to high-priority and latency-sensitive traffic. By listening to the TIM element or the MLTI element in the beacon frame, the non-AP STA can be made aware of the presence or absence of buffered data for it. For example, if there is traffic, the non-AP STA can send a PS-poll or a QoS frame to the AP to get the buffered traffic. After receiving this data, the AP can indicate the end of the traffic by using more data bits. Thereafter, the STA can resume to the sleep state to save power. However, if there is no traffic indicated in the TIM element from the beginning, the STA can directly go to the sleep state.

[0085] The current mechanism for traffic indication only indicates the presence of buffered traffic at the AP for each beacon. Upon receiving a TIM bit set to 1, the non-AP STA transitions to an awake state and sends a PS-Poll to get the traffic. It is not known how long it will take for the target non-AP STA to win channel access to send the PS-Poll or when the AP intends to send the buffered traffic to the STA. These uncertainties waste power as the STA can be in an extended awake mode while waiting for these events to occur. Power consumption can be particularly significant when operating in higher frequency bands, such as in mmWave channels. As an example, using multi-link operation (MLO), the AP can intend to serve a marginal STA at a specific time within the beacon interval. If this information is not provided to the non-AP STA, the non-AP STA will waste power by unnecessarily waking up too early. To remedy this and other shortcomings of traditional wireless systems, a mechanism is needed for an AP or AP MLD to recommend a time at which it intends to serve an associated non-AP STA or non-AP MLD on one or more links.

[0086] Figure 4 An example timing diagram of current AP / beacon acquisition of service is shown. For example, Figure 4 An example of the current mechanism for traffic indication for STAs is shown, which has shortcomings. In Figure 4 In the example, a periodic beacon signal 403 is broadcast from an AP 401 and received by an example non-AP STA1 411. Assume in this figure that at time period 419, STA1 (now awake) is unable to win channel access due to high contention and channel congestion, which results in increased power consumption as a function of the duration and amount of channel contention. Shortly thereafter, at time period 421, assume that STA1 411 is able to win channel access. STA1 sends a PS-Poll 407. The PS-Poll is a control frame sent by a STA to an AP after receiving a beacon containing the STA AID in the TIM. After sending an ACK to the STA and keeping the STA awake for an additional time period 425 to receive service, the AP finally services a message 427 to the non-AP STA. The destination STA1 411 provides a block acknowledgement 409 after successfully receiving the message 427. The beacon 403 is then sent in a periodic manner.

[0087] As Figure 4As shown, at the example activity proximity start, STA1 411 can wake up to receive the next beacon and TIM. Among other things, the traffic indication map only indicates the presence of buffered traffic at the AP in every beacon. Upon receiving a TIM bit set to 1, the non-AP STA transitions to the awake state and sends a PS-poll to get the data. In doing so, the non-AP STA can encounter at least two types of delays. First, there is no knowledge of how long it will take for the non-AP STA to win channel access (419) to send a PS-poll 407 to the AP, or when the AP intends to or is able to send buffered traffic to the STA (427). This lack of knowledge about these types of unnecessary delays results in potential significant power waste. Power consumption waste can be particularly pronounced in millimeter wave links, as millimeter wave links already involve using high energy transmission high frequency bands, the more non-AP STAs are in this mode, the worse the problem gets. Moreover, in some cases, the non-AP STA can not be able to send a PS-poll, either due to hardware that can be involved or low quality link margin limitations. In particular scenarios such as multi-AP coordination, the AP can intend to serve a border STA, for example, at a specific time within the TBTT. If this information is not provided to the non-AP STA, the latter entity will still waste power due to early wake up as described above. The main reason for encountering this problem is the absence of a mechanism for the AP (or AP MLD) to recommend the time at which the AP intends to serve the corresponding non-AP STA or non-AP MLD on one or more links.

[0088] Accordingly, the present disclosure introduces various features that overcome these limitations. Among other benefits, the availability of this advanced knowledge helps non-AP STAs determine when they should transition to the awake state, which in turn improves the quality of overall network management, reduces latency, enables efficient multi-AP coordination, and more efficiently saves STA power.

[0089] Initially, while the written description generally focuses on the terms AP and non-AP STA in connection with one embodiment, these embodiments are equally applicable to recommendations sent by an AP MLD to a corresponding non-AP MLD, including the case where the recommendations can extend to one or more links.

[0090] To this end, various features described further below include embodiments directed at least to: (1) methods and apparatuses to provide for an AP MLD to indicate to one or more AP MLDs a recommended wake-up time for a non-AP MLD on one or more links; (2) methods and apparatuses to provide for an AP MLD to provide a long-term recommendation of a periodic wake-up time to one or more corresponding non-AP MLDs; (3) methods and apparatuses to provide for an AP MLD to provide a long-term recommendation of a wake-up time to one or more corresponding non-AP MLDs within a periodic service period (SP); (4) methods and apparatuses to provide for a STA to request a wake-up time recommendation from an AP and rules for a non-AP STA to comply with when waking up at the recommended time; and (5) unique variations of these features and solutions for both APs and STAs to maximize power saving and network QoS when employing these techniques.

[0091] Thus, in one aspect of the disclosure, an AP transmits a wake-up time recommendation element (WTRE) to indicate to one or more respective STAs a time at which the AP recommends each STA to wake up to get data. Figure 5a An example of a timing diagram 500A having an AP beacon signal 502 including a wake-up time recommendation element (WTRE) 504 is shown in accordance with an embodiment. In this illustration, the AP is associated with STA1.

[0092] It should be noted that in some embodiments, WTRE 504 may be attached to or included in the corresponding beacon signal, but this is not always the case. WTRE 504 may be sent at any suitable time after a beacon with relevant information about the transmission. When a buffer unit (BU) is intended to be sent, WTRE 504 may be sent by the AP to indicate to one or more corresponding STAs the recommended time for waking each device. In embodiments, WTRE 504 may be carried in an existing broadcast frame, unicast frame, or new action frame. WTRE elements typically include different subfields, each of which may include encoded information. The subfields or the information encoded therein may include, for example, an indication of the time each of the STAs should wake up, as indicated when the AID of the associated STA providing the WTRE 504 is provided. This time may be encoded, for example, in a timing unit (TU) or as an identifier of the start time of a beacon interval segment. In the example of MLO, this time may correspond to the time synchronization function (TSF) of the link on which the indication is provided. In other embodiments, this time may refer to the time synchronization function (TSF) of the link to which the recommendation is applied. The time in WTRE can further correspond to an indication of the duration for which the recommendation remains valid where the technique applies. In other embodiments, the time can indicate whether the recommendation is a soft recommendation (optional) or a hard recommendation (mandatory), optionally in conjunction with the purpose of the recommendation. In the case of MLO, the time can include an indication of the link ID for which the recommendation is valid. In some embodiments, the time can include an indication of the number of STAs assigned to the same wake-up time or the sequence number of the STAs among those assigned to the same wake-up time. In other implementations, the time can include an indication that the AP will allocate downlink resources, uplink resources, or both for transmission at the recommended wake-up time. Additionally, in some embodiments, the time can include an indication of whether an acknowledgment is sent for the wake-up time recommendation in WTRE 504. This acknowledgment can be sent, for example, on the link on which the recommendation was sent or on the link to which the recommendation applies, the latter being in the case of MLO. Figure 5a In this context, it is assumed that STA1 is made of WTRE 504 (e.g., Figure 5a The recommended wake-up time 506 is provided. In one embodiment, the AP can divide each beacon interval (BI) into a constituent segment. The STA1 can wake up in time to acquire the BU at the recommended wake-up time without incurring significant or unnecessary power loss.

[0093] Figure 5bAn example of a timing diagram 500B showing a signaling field with multiple beacons and including information about a WTRE according to an embodiment is shown. In this example, the AP can choose to divide each BI 508.1, 508.2, and 508.3, etc. into 2 X segments, where in this example 2 X = 4. In the WTRE element 504 (e.g., Figure 5a ) associated with the beacons, the AP can indicate in the BI segment allocation list (shown here as the last segment in the identified WTRE element 555) for each STA whose TIM bit is set to 1 starting from a certain AID k, the recommendation of the BI segment in which the AP intends to serve the STA. The value of k can be indicated in the AID offset subfield of the wake-up time control field. The value of X (in this case log2 ([number of segments]) can be indicated in the num segments exponent (X) subfield of the wake-up time control field. It should be noted that for clarity, the WTRE element 555 is measured in units of octets (bytes) while the wake-up time control subfield is expressed in bits.

[0094] Still referring to Figure 5b , the BI segment indication for the mth AID whose TIM bit is set to 1 (counting from AID k) is carried in bits (m-1)X+1 to mX of the BI segment allocation list. The WTRE can be sent in the beacons 508.1, 508.2, etc. or in a broadcast, multicast, or unicast frame within the beacon interval following this beacon. The beacons are separated by a beacon interval, which in this example is divided into four segments - segments 0-3.

[0095] Figure 6 An example beacon interval (BI) segment allocation list field for a WTRE according to an embodiment is shown. Figure 5a The principles of Figure 6 extend to the figures of Figure 5a and Figure 5b where a timing diagram 500A is disclosed according to an embodiment for providing a recommended wake-up time, the timing diagram 500A having an AP beacon signal 502 ( Figure 5a ) / 508.1-508.3 ( Figure 5b ) and including a wake-up time recommendation element (WTRE) 504 ( Figure 5a ). In one case, the recommended segment can be limited to the link on which the WTRE 504 is sent. In Figure 6In the TIM element, the entries of the partial virtual bitmap 604 are divided into three categories: (1) bitmap offsets, (2) AIDs without wake-up time recommendations, and (3) AIDs with wake-up time recommendations. The service indication virtual bitmap line 612 and the partial virtual bitmaps in TIM 604 correspond to existing bitmaps already present in the beacon. The third line shows the encoding of the WTRE 555 BI segment allocation list and its dependencies on these existing bitmaps. Figure 6 In the middle, WTRE 555 ( Figure 5b The bits of the BI segment allocation list can be organized as shown in 606, where each STA with a value of 1 for its portion of the virtual bitmap, starting from the initial AID k, sequentially indicates each segment. The value of AID k is in Figure 5b The AID offset field of WTRE 555 indicates this. In this embodiment, the BI segment recommendation element 606 may correspond to the beacon segment of the link that sent WTRE 504 or to the beacon segment of the link to which the recommendation is targeted. In this embodiment, the wake-up recommendation 506 applicable to STA1 may be stored in WTRE 504, and in some cases may also include the purpose of the recommendation or whether the recommendation is hard or soft (mandatory or optional). Figure 6 The data provides a mechanism for AP MLDs to indicate their recommended wake-up times on one or more non-AP MLDs. Figure 5a An example is shown whereby an AP or AP MLD indicates to one or more associated non-AP STAs or a non-AP MLD when it intends to serve them on one or more links. This mechanism helps non-AP STAs determine when they should transition to a wake-up state. These processes also aid in network traffic management, latency reduction, multi-AP coordination, and significant power savings, to name just a few benefits.

[0096] therefore, Figure 6 The bitmap includes a cross-link indicator, which enables links in an MLO scenario to discover whether wake-up times are associated with these non-AP links. Therefore, in a first embodiment involving MLO, the recommendation segment may apply only to the link sending the WTRE. In another embodiment involving MLO, there may be a link ID or link bitmap field indicating all applicable links. In this case, the segment indicator may correspond to the beacon segment sending the recommendation, or it may correspond to the beacon segment of the link to which the recommendation is targeted.

[0097] Figure 7An example of using a Multi-User Request Transmit (MU-RTS) trigger frame as a standard for wake-up recommendation according to an embodiment is shown. In this implementation, the wake-up time recommendation indication can be carried in the trigger frame, such as the MU-RTS frame 730 shown here, the Buffer Status Report Polling (BSRP) frame, or a unique variant of such a frame. For each STA to which the wake-up time recommendation is targeted, the AP may include a user information list field 731 having user information subfields {1-N} 732, each user information subfield corresponding to the AID of that STA within the trigger frame. The user information list field 731 may have a format similar to that of other embodiments, since the user information list field 731 is divided into N user information fields 732. Each of the N user information fields 732 may also include a wake-up time recommendation (WTR) indication subfield 735. The purpose of the latter field in this embodiment is to indicate the applicable user information field 732 for the wake-up time recommendation associated with the STA. The user information field 732 may also include a service type subfield 738 indicating the type of service to be delivered at the indicated wake-up time. Examples of the "type" of service include downlink or uplink services. In some configurations, the "reason code" field may be included in the user information field 732 to identify the reason for the wake-up time recommendation. In the case of MLO, the link to which the recommendation applies may also be located in the link ID subfield 737 of the user information field 732 of the trigger frame. In another configuration, STAs are expected to send a response to the trigger frame indicating whether they will comply with the recommendation. This response may be solicited by the AP on the link where the trigger frame was sent, or on the link where the recommendation is deemed applicable.

[0098] In one embodiment, wake-up time recommendation element 504 ( Figure 5a It can provide BI segment indication for multiple links. Figure 8a An example of a WTRE element 800A according to an embodiment is shown, which provides BI segment indications for multiple links by indicating the link set size. The WTRE element 800A in this embodiment includes a field element ID 802, a length 804, an element ID extension 806, a wake-up time control 808a, and a BI segment allocation list 810. In this configuration, a link set size subfield may be present in the wake-up time control field 808(a) of the WTRE element 800A to indicate the number of links for which a recommendation is provided. For example, if the link set size is set to the value L, the recommendation is for link IDs {0, 1, ..., L-1}.

[0099] In some embodiments involving MLOs, there can be a link ID or link bitmap field indicating all applicable links. In this case, the segment indication can correspond to the beacon segment transmitting the recommendation, or alternatively, the segment indication can correspond to the beacon segment of the link they are directed to. In another variant, there can be a recommendation type field (e.g., a reserved subfield in the wake-up time control field 808a) in the WTRE message element 800A that provides additional details, flags, or codes about the purpose and nature of the recommendation. Alternatively or additionally, in this embodiment, instead of a link set size subfield, there can be a link ID bitmap subfield to indicate that the BI segment of the provided WTRE 800A is applicable to all link IDs.

[0100] Thus, in another example, Figure 8b An embodiment of a WTRE element 800B with a subfield using AID offset and a link ID bitmap subfield in the wake-up time control field 808b is shown according to another embodiment. In this example, as described above, the link set size is replaced by the link ID bitmap subfield of the wake-up time control field 808b for identifying all links to which the WTRE is to be applied. The BI segment indication can be carried in one or more per-link BI segment allocation list subfields of the BI segment allocation list field 810 of the WTRE element 800B.

[0101] Figure 9 An example of a traffic indication virtual bitmap 900 is shown according to an embodiment. The bitmap is indicated using reference numeral 906. At 906 is a BI segment allocation list field. The BI segment indication can be carried in one or more per-link BI segment allocation list fields 915 of the WTRE. The mthper-link BI segment allocation list field of the BI segment allocation list field 906 carries an indication for the mthAID for which the TIM bit is set to 1, counting from AID k. Each per-link BI segment allocation list can have XLbits, where L is the value X in the link set size of the wake-up time control field 808b (or the number of bits set to 1 in the link ID bitmap). The first X bits of the list indicate the BI segment for link ID 0 (or the first link for which the bit is set to 1 in the link ID bitmap), the next X bits for link ID 1 (or the second link for which the bit is set to 1 in the link ID bitmap), and so on. In Figure 8b Figure 9 ​In this case, the bitmap offset 922 traverses the first column of the traffic indication virtual bitmap 902 and the partial virtual bitmap in the TIM 904; the AIDs 924 without wake-up time recommendation traverse the second column of the bitmap 902 and the partial virtual bitmap in the TIM 904; and the AIDs 926 with wake-up time recommendation traverse the third column of the rows 902, 904, and 906. The first and last numbers in the row 904 (via the arrows) correspond to the corresponding per-link BI segment allocation list for AID k and AID k+5.

[0102] In another aspect of the disclosure, the AP can segment the beacon into different segments, as in the previous embodiments.

[0103] Figure 10a and Figure 10b WTRE elements 1000A and 1000B are shown, respectively. The WTRE element 1000A has an Association Identifier (AID) bitmap element 1010 to identify all AIDs for which a wake-up time indication is applicable. The purpose of these fields is to provide a common wake-up time for all AIDs identified in the bitmap 1010. That is, the same wake-up time indicated using the BI segment field 1012 in the WTRE element can be assigned for all indicated AIDs Figure 10a of 1000A) or a wake-up time Figure 10b of the WTRE 1000b). Referring to Figure 10a The same wake-up time indicated using the BI segment field 1012 can be assigned for each of the indicated AIDs. The BI segment field 1012 indicates the start time at which the AP is requesting the STA to initiate a wake-up within the segment at the beacon interval. In one embodiment, instead of the BI segment field 812, the WTRE field 1000B is introduced, which includes a wake-up time subfield 1014, as shown in Figure 10b The wake-up time subfield 1014 indicates the time at which the AP indicates the STA to wake up. The wake-up time can be in TUs and can indicate the number of TUs from the most recent Target Beacon Transmission Time (TBTT) at which the STAs identified in the AID bitmap element 1010 are requested to wake up. In one embodiment involving MLO, there can also be a link field indicating the link for which the recommendation is valid. In this case, the segment indication can correspond to the beacon segment in which the recommended link is transmitted, or to the beacon segment for which the recommendation is directed. Figure 10b A WTRE using a wake-up time field indicating the time at which the AP indicates the STA to wake up, according to an embodiment, is shown.

[0104] Figure 11Another timing diagram 1100 is shown with a sequence of beacons 1101.1, 1101.2, 1101.3 and WTRE element 1118 using AID offset and random access resource units (RA RUs) according to an embodiment. Each BI segment can be initiated by the AP with a trigger frame to enable all awakened STAs to send respective PS polls to the AP in parallel via uplink orthogonal random access (UORA). Subsequently, the AP can perform multi-user transmission to the STAs following these operations. Alternatively or additionally, the AP can send a buffer status report poll (BSRP) trigger frame to the STAs in response to which the AP receives buffer status reports from the STAs. In an embodiment, the provision of such a trigger frame at the beginning of the segment can be optional. The presence of the trigger frame in the segment can instead be indicated by a RA RU subfield nested within the wake-up time control field 1108. The identification of the elements in question, their length and extension are marked as 1102, 1104 and 1106, respectively. The variable BI segment allocation list 1111 functions similarly to those in the previous embodiments.

[0105] When the recommendation is sent on one link but is actually intended for another link, the wake-up time is selected taking into account the delay incurred by the receiver to pass the wake-up recommendation to the target link. The STA can indicate this phenomenon (e.g., “cross-link wake-up delay”) to the AP in its Ultra High Reliability (UHR) physical layer signaling or its medium access control (MAC) capabilities element during the association procedure.

[0106] In another aspect of the disclosure, if the AP has a BU for a STA, the AP can use the WTRE to indicate a so-called “long-term” recommendation of the time at which the AP intends to serve the STA for a subset of associated non-AP STAs or MIDs. Figure 12A WTRE element 1200 using subfields for wake-up time control is shown in accordance with an embodiment. In one configuration, an indication of the time at which the intended wake-up is specified can be carried in the BI segment allocation list 1212. However, unlike the previous embodiment, the AID bitmap field 1210 of the WTRE can be used to identify the STA for which the BI segment indication is provided. In addition, the AID bitmap field can carry an AID bitmap element 1210 that provides a list of AIDs of STAs associated with the AP. The BI segment indication for the mth AID identified in the AID bitmap can be carried in bit { (m-1) X + 1 - mX} of the BI segment allocation list field. The WTRE element 1200 can be sent in a broadcast frame and can apply to each target beacon transmission time (TBTT) until it is torn down or until the indicated expiration TBTT as indicated in the NUM TBTT subfield of the wake-up time control field 1208. In one embodiment, the element can be an extension of an existing frame, such as the existing Link Recommendation frame. In one embodiment involving MLO, the recommended time can apply to all enabled links of the non-AP MLD. In another configuration involving MLO, the recommended time can apply to the link from which the WTRE element 1200 is sent. In one embodiment involving MLO, there can be a link ID bitmap or link ID field in the WTRU element 1200 that identifies the link to which the wake-up recommendation applies. In one embodiment, per-link BI segment indication can be provided in the WTRE 1000 as in the above-described embodiments. In yet another configuration, a recommendation type field (RTF) can be provided. The RTF identifies the purpose of the recommendation and related factors, such as whether the recommendation is a hard or soft recommendation. In one embodiment, instead of the BI segment allocation list 1212, the WTRE 1200 can incorporate a BI segment or wake-up time field (as in the above-described embodiments). In this case, all AIDs identified in the WTRE are assigned the same long-term wake-up time. Multiple WTREs can be sent to cover STAs recommended to wake up at different long-term wake-up times.

[0107] Figure 13Examples are shown of transmitting WTREs 1300a and 1300B to non-AP STAs / MLDs in individually addressed frames, according to embodiments. In the example of 1300A, the AP can transmit a WTRE to a non-AP STA / MLD in an individually addressed frame to indicate to the STA a recommendation of the time at which the AP intends to serve the STA. For example, the indication of the time can be carried in the wake-up time field 1314 or in another available field. In one embodiment involving MLOs, the recommended time can apply to all enabled links in the link ID bitmap of the wake-up time control field 1308 of the non-AP MLD that includes an identification of the links to which the wake-up recommendation applies. In summary, in the WTRE element 1300A with element ID 1302, length 1304, element ID extension 1306, and wake-up time control field 1308, the wake-up time is stored in the wake-up time field 1314. In the WTRE element 1300B, the elements are the same except for the last field or wake-up time list 1316. The wake-up time list can be a variable field containing multiple wake-up times that can be mapped to multiple links as indicated in the link ID bitmap of the wake-up time control 1308b.

[0108] For example, in cases where certain frequency bands are considered optimal while other frequency bands can be bandwidth overloaded, the technique advantageously enables the exchange of data on one or more designated links. In another example, per-link wake-up time indications can also be provided in the WTRE 1100B (as in the earlier example), as depicted in Figure 11 In additional embodiments, a recommendation type field identifying the purpose of the recommendation or whether the recommendation is a hard or soft recommendation can be included within the WTRE 1100B. For Figure 13 , the AP can also transmit a WTRE to a non-AP STA or MLD in an individually addressed frame to indicate a single time recommendation, as described above.

[0109] Figure 14 An example timing diagram 1400 is shown in which a STA (“STAl”) can negotiate with an AP to provide an additional wake-up delay 1424 for addition to a recommended wake-up time, according to embodiments. The non-AP STA (“STAl”) can optionally negotiate with the AP 1410 to require the AP to provide a WTRE 1422 to STAl. Thereafter, the AP 1410 can provide a response frame indicating the success or failure of the operation.

[0110] In one embodiment, if the WTRE recommendation 1422 indicated by the AP 1410 after sending the beacon 1402 is a hard recommendation, then STA1 can not violate it and / or can not need to explicitly send a PS-poll frame to indicate that STA1 has transitioned to the awake state. In another example, at the wake-up time that is the recommended wake-up time plus a delay of the wake-up delay 1424, each of the indicated STAs can suppress transmissions for a grace period from the start of the indicated wake-up time. This option can be implemented when, for example, the AP indicates that it will provide a random access resource unit (RA-RU) or triggered uplink access for the transmission of PS-poll or data. If this is the case, then each of the indicated STAs can wake up at any of these times:

[0111] (i) At the indicated wake-up time. In one variant, although the STA wakes up at the indicated wake-up time, its backoff counter can be set based on the number of STAs with lower AIDs in the WTRE that have been assigned the same wake-up time.

[0112] (ii) At the delayed wake-up time, where the delay can be determined by how many STAs with lower AIDs in the WTRE are assigned the same wake-up time.

[0113] (iii) At a randomly delayed wake-up time, where the range of the random delay can be determined by how many STAs in the WTRE are assigned the same wake-up time. This is to minimize the chance of collision.

[0114] In short, Figure 14 The delayed wake-up time configuration 1424 is shown. The delayed wake-up time represents the difference between the recommended wake-up time of STA1 and the actual wake-up time of STA1. Subsequently, when a new beacon 202 is sent, another cycle is initiated. It should be noted that this figure is applicable to the scenario where there are several other stations (STAs) assigned the same wake-up time (assuming no RA-RU allocation is made), and this station (STA) performs delayed wake-up based on this. The WTRE can also have an AID bitmap field that identifies the AIDs of the STAs that are members of this particular SP and for which it provides the wake-up time period. In a configuration that includes a wake-up time field, the wake-up time can indicate an offset time from the start of the SP. The WTRE can send as a group addressed frame at the start of each such SP, or it can not send as frequently in the case of long-term recommendations.

[0115] In short, in many cases, this embodiment eliminates the need for PS-poll, which consumes resources, and provides lower latency. Furthermore, reducing the chance of collision can help increase the total bandwidth of the system.

[0116] In summary, the AP can use the wake-up recommendation to recommend a wake-up time within a specific periodic service period (SP) instead of the entire beacon interval as depicted in the embodiments above. Such periodic interval can be, for example, a broadcast TWT service period or a restricted TWT service period or a beacon interval following a DTIM beacon. In this way, the existing concept of "BI segment" can be replaced by "SP segment" providing a SP segment allocation list subfield in the WTRE as described in more detail below.

[0117] Figure 15 An example flow diagram 1500 of a procedure for recommending a wake-up time by an AP according to an embodiment is shown. While Figure 15 A sequence of steps for wake-up time recommendation by an AP is shown, but other possibilities can exist without departing from the scope of the disclosure. That is, the scope of this example flow diagram in Figure 15 The scope of this example flow diagram in

[0118] Reference is first made to Figure 15 At block 1502, the AP can receive a trigger to initiate a wake-up time recommendation. At block 1504, the AP generates and sends a WTRE. If needed, the WTRU is configured by the AP to send periodically. In turn, if applicable at block 1506, the AP sends a trigger frame for PS-poll transmission at the recommended wake-up time. Otherwise, if applicable at block 1508, the AP provides RA-RU resources for UORA at the recommended wake-up time.

[0119] Figure 16 Another example flow diagram 1600 of a procedure for recommending a wake-up time by an AP according to an embodiment is shown. While Figure 16 A sequence of steps for wake-up time recommendation by a STA is shown, but other possibilities can exist without departing from the scope of the disclosure. That is, the scope of this example flow diagram in Figure 16 The scope of this example flow diagram in

[0120] Figure 16 The operations in Figure 15The operations in FIG. 16 are performed by the STA. Referring first to block 1602, the STA sends a wake-up time recommendation request to the AP, if applicable in the context of receiving a suitable prompt. Next, at block 1604, the STA receives a wake-up time recommendation from the AP. At block 1606, assuming the wake-up time recommendation has been received from the AP, the STA wakes up at the recommended wake-up time for receiving or transmitting a BU. At block 1608, the STA follows the appropriate back-off procedure at the wake-up time to initiate transmission while reducing the likelihood of collision. At block 1610, the STA transmits or receives the BU. At block 1612, the STA goes back to sleep. The STA can repeat the process of FIG. 16 for each BU. Figure 12 In some embodiments as shown in FIG. 17, for example, there will be a delay between the recommended wake-up time of a STA and its actual wake-up time. The end result of these processes is a fast network with reduced latency, less network congestion, less network idle time, greater certainty, and lower power consumption.

[0121] In another aspect of the disclosure, the AP can use the wake-up recommendation method described above for recommending a wake-up time within a specific service period (SP) instead of the entire beacon interval. Figure 17 Examples of this technique are set forth in FIGS. 16 and 17, Figure 17 is a timing diagram 1700 showing a beacon 1702.1 and three segments of a service period 1723. Figure 17 is shown. This periodic interval can be, for example, a broadcast TWT SP, a restricted TWT SP, or a beacon interval following a Delivery Traffic Indication Message (DTIM) beacon.

[0122] In this aspect, the concept of "BI segment" can be replaced with "SP segment," and the SP segment allocation list subfield can be included in the subject WTRE element. The WTRE can also include an AID bitmap field that identifies the AIDs of STAs that are members of this particular SP and for which a wake-up time recommendation is provided. Thus, for example, Figure 17 is shown. Each SP 1723 or 1725 can be further divided into SP segments. While the number of SP segments can vary according to embodiments, for example, Figure 15 Each SP in FIG. 17 includes three SP segments. In embodiments that include a wake-up time field, the wake-up time can indicate an offset time from the start of the SP. The wake-up time recommendation element can be sent as a group addressed frame at the start of each such SP (e.g., SP 1723 or SP 1725), or in the case of a long-term recommendation, the WTRE can be sent infrequently, for example, only when a schedule change occurs.

[0123] The use of the terms "a" and "an" and "the" and "said" and "the" are intended to include both singular and plural, unless otherwise indicated. For example, the term "a" module can mean one or more modules. An element preceded by "one or more of" does not, without further constraints, foreclose multiple elements of the same type.

[0124] Headings and subheadings, if any, are for convenience only and do not limit the application. The word "exemplary" is used herein to mean serving as an example, or illustration, or instance. With respect to the use of terminology, such as "comprising", "comprises" and "comprised of", "containing", "contains", "containing" and "contains", "including", "includes", "including" and "includes", "having", "has", "having" and "has", "involving", "involve", "involving" and "involve", "providing", "provides", "providing" and "provides", "supplying", "supplies", "supplying" and "supplies", "varying" and "varies", "wherein", "where" and "whereby", these terms are intended to be equivalent.

[0125] Phrases such as one aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, one configuration, the configuration, another configuration, some configurations, one or more configurations, the subject technology, the disclosure, the present disclosure, other variations thereof, and the like are used for convenience and do not refer to a necessity of related disclosures with the phrases. The related disclosures with the phrases can be applied to all configurations or one or more configurations. The related disclosures with the phrases can provide one or more examples. Phrases such as one aspect or some aspects can refer to one or more aspects, and vice versa, which is equally applicable to other aforementioned phrases.

[0126] The phrase "at least one of followed by a series of items and the term "and" or "or" preceding the series of items, modifies the entire list of items, rather than each member of the list. The phrase "at least one of" does not require selection of at least one item; rather, the phrase allows for inclusion of less than all of the items, and / or inclusion of all of the items, and / or inclusion of each of the items. For example, the phrase "at least one of A, B, and C" or "at least one of A, B, or C" can refer to only A, only B, or only C; to any combination of A, B, and C; and / or to at least one of A, B, and C.

[0127] It should be understood that a specific order or hierarchy of steps, operations or processes depicted in any of the figures provided can be modified as desired. Specifically, but without limitation, the steps, operations or processes can be performed in an order other than that depicted in the figures. Some steps, operations or processes can be performed simultaneously, or can be performed as part of one or more other steps, operations or processes. Additional or fewer steps, operations or processes can be employed. The accompanying method claims, if any, set forth elements of the various steps, operations or processes in an example order. The methods, if any, are not limited to the specific order or hierarchy presented in the claims. The various elements of the steps, operations or processes can be performed in serial, parallel, or in different order. It should be understood that the descriptions, illustrations and figures set forth herein are by way of example, and various configurations can comprise different steps, operations or processes without departing from the scope of the claims. The various claims set forth unique combinations of elements of the various aspects of the technology.

[0128] This disclosure is directed to enabling any of those skilled in the art to practice aspects described herein. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. The present disclosure provides various examples of the subject technology and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the principles described herein can be applied to other aspects as well.

[0129] All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether these disclosures are explicitly recited in the claims. No element, component, or method step in the claims is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited in the claims as “means plus function.” Any need to express the elements articulately recited in the claims in the language of 35 U.S.C. § 112(f) is hereby withdrawn, in favor of a clear intent to claim only the specific features set forth in the claims.

[0130] The title, background, brief summary, abstract, and drawings are hereby incorporated into this disclosure and serve as illustrative examples of the disclosure, but not limiting descriptions. They are understood to not limit the scope or meaning of the claims at the time of their submission. Furthermore, in the DETAILED DESCRIPTION, it can be seen that a description provides illustrative examples and, in an effort to simplify the disclosure, various features are combined in various implementations. This method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are explicitly recited in each claim. Rather, as the appended claims reflect, inventive subject matter lies in fewer than all features of a single disclosed configuration or operation. The claims are hereby incorporated into the DETAILED DESCRIPTION, with each claim standing on its own as a separately claimed subject matter.

[0131] 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 claims, and to include all legal equivalents. None of the claims are intended to incorporate by reference the application as filed unless specifically indicated.

Claims

1. An access point (AP), comprising: Memory; and A processor coupled to the memory, the processor being configured to: Send a Wake-up Time Recommendation Element (WTRE) to one or more stations, the WTRE including at least (i) an identifier of one or more stations; and (ii) a recommended wake-up time, which is used by the one or more stations to start sending or receiving data after the WTRE is sent; and At the recommended wake-up time, receive an indication from one or more stations that the one or more stations are ready to exchange data with the AP.

2. The AP according to claim 1, wherein, The recommended wake-up time is determined based on at least one of the following: Time synchronization function corresponding to the expected wake-up time; One or more transmitting units, the one or more transmitting units corresponding to the time gap between the transmission of the WTRE and the expected wake-up time, or The identifier of the beacon segment corresponding to the expected wake-up time, wherein the beacon interval after the transmission of the WTRE is divided into beacon segments of equal length.

3. The AP according to claim 1 or 2, wherein, The WTRE includes an indication of whether the recommended wake-up time is used for transmission of: downlink traffic from the AP to the one or more stations; uplink traffic from the one or more stations to the AP; or bidirectional traffic to the one or more stations.

4. The AP according to any one of the preceding claims, wherein, The WTRE includes an indication of whether the recommended wake-up time is used for transmissions initiated or triggered by the AP.

5. The AP according to any one of the preceding claims, wherein, The WTRE includes: An indication regarding whether the at least one recommended wake-up time is optional or mandatory; and The purpose of the recommendation.

6. The AP according to any one of the preceding claims, wherein, The AP is an AP multilink device (MLD) that includes one or more affiliated APs, and the AP MLD establishes one or more links, each link being associated with a corresponding AP among the one or more affiliated APs; and During Multi-Link Operation (MLO), the WTRE is configured to indicate one or more links to which the WTRE is valid.

7. The AP according to any one of the preceding claims, wherein, The WTRE includes the number of stations assigned to the same recommended wake-up time or the sequence number of the stations assigned the same recommended wake-up time.

8. The AP according to any one of the preceding claims, wherein, The WTRE includes an indication of whether the recommendation is a long-term recommendation that is continuously used for at least one station over a specified period of time.

9. A station in a wireless network, comprising: Memory; A processor coupled to the memory, the processor being configured to: Send a request to the access point (AP) to issue the Wake-up Time Recommendation (WTRE) element; The WTRE is received from the AP, wherein the WTRE includes at least (i) an identifier of one or more stations; and (ii) a recommended wake-up time, which is used after the WTRE is sent for the one or more stations to begin sending or receiving data at the recommended wake-up time; Wake up at the recommended time; and Send an instruction at the recommended time that the station is ready to exchange data with the AP.

10. The station according to claim 9, wherein, The processor is also configured to: In the event of an impending or existing conflict between the various transmissions, a backoff process identified by the AP is followed; and After the backoff process is completed, the transmission is re-initiated at a specified time to obtain services from the AP.

11. The station according to claim 9 or claim 10, wherein, The processor is also configured to: The station receives a trigger frame from the AP, the trigger frame requesting the station to send a power-saving PS polling frame at the recommended wake-up time; The PS polling frame is sent to the AP at the recommended wake-up time.

12. The station according to any one of claims 9 to 11, wherein, One or more of the stations mentioned include non-AP stations.

13. The station according to any one of claims 9 to 12, wherein: The WTRE includes an indication of the duration for which the recommended wake-up time will remain valid; and The station is configured to wake up at the recommended wake-up time to perform frame exchange with the AP.

14. The station according to any one of claims 9 to 13, wherein, The station is a non-AP multi-link device (MLD), which includes one or more affiliated non-AP stations, and the non-AP MLD establishes one or more links, each link being associated with a corresponding one of the one or more affiliated non-AP stations; and During Multi-Link Operation (MLO), one or more affiliated non-AP stations transition to a wake-up state on a recommended link at the recommended wake-up time, the recommended link being indicated by a link identifier included in the WTRE.

15. The station according to any one of claims 9 to 14, wherein, The WTRE includes an indication of whether the recommendation is a long-term recommendation that is continuously used for at least one station over a specified period of time.

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