Apparatus and method for low power listening mode

Abstract

According to one aspect of the present invention, there is provided a wireless communication method for a first node. The wireless communication method may include generating, by at least one processor, a first low-power listening (LPL) frame having a first LPL subfield set to "enabled." The method may include transmitting, by a communication interface, the first LPL frame having the first LPL subfield set to "enabled" to a second node. The method may include enabling, by the at least one processor, an LPL mode after transmitting the first LPL frame having the first LPL subfield set to "enabled" to the second node.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. provisional application Ser. No. 63 / 396,337, filed Aug. 9, 2022, entitled "LOW POWER LISTENING MODE," the entire contents of which are incorporated herein by reference. [Background technology]

[0002] FIELD OF THE INVENTION Embodiments of the present invention relate to apparatus and methods for wireless communication.

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. In wireless local area network (WLAN) communications (such as Wi-Fi), cellular communications (such as 4th-generation (4G) Long Term Evolution (LTE) and 5th-generation (5G) New Radio (NR)), the Institute of Electrical and Electronics Engineers (IEEE) and the 3rd Generation Partnership Project (3GPP) have defined various operations related to power saving modes. Summary of the Invention

[0004] According to one aspect of the present invention, there is provided a wireless communication method for a first node. The wireless communication method may include generating, by at least one processor, a first low-power listening (LPL) frame having a first LPL subfield set to "enabled." The wireless communication method may include transmitting, by a communication interface, the first LPL frame having the first LPL subfield set to "enabled" to a second node. The wireless communication method may include enabling, by the at least one processor, an LPL mode after transmitting the first LPL frame having the first LPL subfield set to "enabled" to the second node.

[0005] According to another aspect of the present invention, there is provided a method of wireless communication for a first node, the method may include identifying, by at least one processor, a first EMLSR linkset associated with an LPL mode and an active mode, and transmitting, by a communication interface, a first indication of the first EMLSR linkset associated with the LPL mode and the active mode to the second node.

[0006] According to yet another aspect of the present invention, there is provided a wireless communication device for a first node. The wireless communication device may include at least one processor. The wireless communication device may include a memory storing instructions. The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to generate a first LPL frame having a first LPL subfield set to "enabled." The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to transmit the first LPL frame having the first LPL subfield set to "enabled" to a second node. The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to enable an LPL mode after transmitting the first LPL frame having the first LPL subfield set to "enabled" to the second node.

[0007] According to yet another aspect of the present invention, there is provided a wireless communication method for a first node, the wireless communication method may include receiving, via a communication interface, from a second node, a first LPL frame having a first LPL subfield set to “enabled,” and identifying, by at least one processor, that the first LPL subfield in the first LPL frame is set to “enabled.”

[0008] According to yet another aspect of the present invention, there is provided a method of wireless communication for a first node, the method may include receiving, via a communication interface, from the second node a first indication of one or more EMLSR link sets associated with the LPL mode and an active mode, and identifying, by one or more processors, the one or more EMLSR link sets associated with the LPL mode and the active mode based on the first indication.

[0009] According to yet another aspect of the present invention, there is provided a wireless communication device for a first node. The wireless communication device may include at least one processor. The wireless communication device may include a memory for storing instructions. The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to receive a first LPL frame from a second node, the first LPL frame having a first LPL subfield set to "enabled." The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to identify that the first LPL subfield in the first LPL frame is set to "enabled."

[0010] These illustrative examples are not intended to limit or define the invention, but rather to provide examples for ease of understanding. Additional embodiments are described in additional examples, and further details are provided. [Brief explanation of the drawings]

[0011] [Figure 1] 1 illustrates an exemplary wireless network in accordance with some embodiments of the present invention. [Figure 2] FIG. 2 is a block diagram of an exemplary node according to some embodiments of the present invention. [Figure 3] 1 is a block diagram of an apparatus including a wireless receiver, a wireless network interface, and a host chip according to some embodiments of the present invention. [Figure 4A] FIG. 2 illustrates a call flow of a first exemplary LPL operation of a first node and a second node, according to some embodiments of the present invention. [Figure 4B] FIG. 2 illustrates a call flow of a first exemplary LPL operation of a first node and a second node, according to some embodiments of the present invention. [Figure 4C] FIG. 2 illustrates a call flow of a first exemplary LPL operation of a first node and a second node, according to some embodiments of the present invention. [Figure 4D] FIG. 10 illustrates a call flow of a second exemplary LPL operation of a first node and a second node, according to some embodiments of the present invention. [Figure 5] FIG. 2 illustrates an exemplary LPL frame including multiple subfields, in accordance with some embodiments of the present invention. [Figure 6] 1A-1C are example timing diagrams of LPL mode periods and active mode periods according to some embodiments of the present invention. [Figure 7] FIG. 1 is a schematic diagram of an exemplary Enhanced Multi-Link Single Radio (EMLSR) link set in accordance with some embodiments of the present invention. [Figure 8] FIG. 2 is a diagram of an exemplary EMLSR bitmap field in an Extended Multilink (EML) frame in accordance with some embodiments of the present invention. [Figure 9] FIG. 1 is a schematic diagram of an exemplary sub-multilink device (MLD) linkset according to some embodiments of the present invention. [Figure 10A] 1 is a flowchart of a first exemplary wireless communication method according to some embodiments of the present invention. [Figure 10B] 1 is a flowchart of a first exemplary wireless communication method according to some embodiments of the present invention. [Figure 11] 4 is a flowchart of a second exemplary wireless communication method according to some embodiments of the present invention. [Figure 12A] 10 is a flowchart of a third exemplary wireless communication method according to some embodiments of the present invention. [Figure 12B] 10 is a flowchart of a third exemplary wireless communication method according to some embodiments of the present invention. [Figure 13] 10 is a flowchart of a fourth exemplary wireless communication method according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention and thereby enable those skilled in the art to make and use the invention.

[0013] An embodiment of the present invention will be described with reference to the drawings.

[0014] While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. Those skilled in the art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention. Clearly, those skilled in the art will recognize that the present invention can be used in a variety of other applications.

[0015] In this specification, descriptions such as "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," and "particular embodiments" indicate that the described embodiment may include a particular feature, configuration, or characteristic, but not all embodiments necessarily include the particular feature, configuration, or characteristic. Furthermore, such expressions do not necessarily refer to the same embodiment. Furthermore, when a particular feature, configuration, or characteristic is described in connection with an embodiment, such feature, configuration, or characteristic can be realized by combining it with other embodiments within the knowledge of a person skilled in the art, regardless of whether it is explicitly described.

[0016] Generally, terms can be understood, at least in part, from their usage in context. For example, as used herein, the term "one or more" may be used in the singular sense to describe a particular feature, configuration, or characteristic, or in the plural sense to describe a combination of features, configurations, or characteristics, depending on the context. Similarly, terms such as "one," "an," or "said" are understood to convey either the singular or plural, depending on the context. Additionally, the term "based on" is not intended to convey a necessarily exclusive set of factors, but instead may be understood, at least in part, depending on the context, to allow for the presence of additional factors not necessarily explicitly described.

[0017] Various aspects of wireless communication systems will now be described with reference to various apparatus and methods. These apparatus and methods are described in the following specific embodiments and are illustrated by various blocks, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends on the particular application and design constraints imposed on the overall system.

[0018] The techniques described herein may be used in various wireless communication networks, such as code division multiple access (CDMA) systems, time division multiple access (TDM) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, wireless local area networks (WLAN) systems, global navigation satellite systems (GNSS), and other networks. The terms "network" and "system" are always used interchangeably. A CDMA network may implement radio access technologies (RATs) such as Universal Terrestrial Radio Access (UTRA), evolved UTRA (E-UTRA), CDMA 2000, and the like. A TDMA network may implement a RAT such as Global System for Mobile Communications (GSM). An OFDMA network may implement a RAT such as LTE or NR. A WLAN system may implement a RAT such as Wi-Fi. The techniques described herein may be used for the above wireless networks and RATs as well as other wireless networks and RATs.

[0019] Existing WLAN systems support various station (STA)-based power saving techniques. These power saving techniques include, for example, a sleep mode. A STA can enter a sleep mode when there is a gap in packet exchange between the STA and its corresponding access point (AP). While such a sleep mode can reduce power consumption at the STA during periods of low or no packet exchange, there is an undesirable delay when transitioning from sleep mode to active mode. Therefore, time-sensitive packets may be missed by the STA or may be stuck at the AP due to the delay associated with this transition.

[0020] To overcome the above and other challenges, the present invention enables an exemplary low-power listening (LPL) mode. During LPL mode, a STA may remain awake but monitor only a reduced-size bandwidth (BW) for packets transmitted using a restricted modulation and coding scheme (MCS). In this way, the STA can achieve reduced power consumption while avoiding undesirable delays associated with transitioning from sleep mode to active mode. Additional details of an exemplary LPL technique are provided below with reference to Figures 1-13.

[0021] Although some embodiments are described herein with reference to WLAN or GNSS communication systems, the same or similar techniques may also be applied to cellular communication systems. For example, a UE receiving signals from a 5G NR base station via beamforming and / or millimeter-wave (mmW) signaling may experience multipath issues as these beams may reflect off nearby objects, potentially reducing the accuracy of position determination using these signals. Thus, without departing from the scope of the present invention, the techniques described below may be applied to estimating beam parameter sets used for UE position determination in a cellular communication system.

[0022] 1 illustrates a simplified architecture of a wireless communication system 100 in accordance with certain embodiments presented herein. System 100 may include multiple non-access point (non-AP) STAs, such as user equipment (UE) 120-1 through 120-n (collectively referred to as UEs 120), and multiple AP STAs, such as APs 140-1 through 140-4 (collectively referred to as APs 140), which may communicate via a wireless communication network 130. Examples of UEs 120 include, for example, smartphones, vehicles, wearable devices, laptops, or any other devices capable of providing navigation functionality to users. In some embodiments, wireless communication network 130 may take the form of and / or include one or more wireless local area networks (WLANs) or the Internet. In some embodiments, UEs 120 and / or APs 140 may communicate with server 150 via wireless communication network 130. Although system 100 shows several UEs 120 and APs 140, the number of UEs 120 and APs 140 in a wireless communication network (e.g., a WLAN) can vary depending on various system parameters. In general, system 100 can include fewer or more UEs 120 and / or APs 140.

[0023] In some embodiments, one or more UEs 120 and / or APs 140 in system 100 may include multiple antennas and may support multiple-input multiple-output (MIMO) and / or multi-user MIMO (MU-MIMO). UEs 120 may receive and measure signals from APs 140, which may be used for position determination. In some embodiments, APs 140 may form part of a wireless communication network 130, such as a WLAN. For example, the WLAN may be an IEEE 802.11x network (e.g., IEEE 802.11ax, 802.11ay, or later versions). System 100 may also include or take the form of an Extended Service Set (ESS) network. The ESS network may include multiple appropriately configured basic service set (BSS) networks, independent basic service set (IBSS) networks, ad-hoc networks, or peer-to-peer (P2P) networks (e.g., operating according to Wi-Fi Direct or similar protocols).

[0024] In some embodiments, one or more UEs 120 and APs 140 can communicate via a wireless communication network 130, which can be based on IEEE 802.11 or a compatible standard. In some embodiments, the UEs 120 and APs 140 can communicate using a variant of the IEEE 802.11 standard. For example, the UEs 120 and APs 140 can communicate using 802.11ac in the 5 GHz band, which can support multiple spatial streams including MIMO and MU-MIMO. In some embodiments, the UEs 120 and APs 140 can communicate using several of the above standards, which can further support one or more of Very High Throughput (VHT) and High-Efficiency WLAN (HEW) (as described in the above standards) and / or beamforming based on standardized sounding and feedback mechanisms. In some embodiments, the UEs 120 and / or APs 140 can further support legacy standards for communication with legacy devices.

[0025] In some embodiments, UE 120 and / or AP 140 may be coupled to one or more additional networks, such as a cellular carrier network, a satellite positioning network (shown in FIG. 1), a wireless personal area network (WPAN) access point, etc. (not shown in FIG. 1). In some embodiments, UE 120 and / or AP 140 may be coupled to a wireless wide area network (WWAN) (not shown in FIG. 1), which may be a code division multiple access (CDMA) network, a time division multiple access (TDM) network, a frequency division multiple access (FDMA) network, an orthogonal frequency division multiple access (OFDMA) network, a single-carrier frequency division multiple access (SC-FDMA) network, Long Term Evolution (LTE), 5G New Radio (NR), WiMax, etc.

[0026] The UE 120 and AP 140 in any of the above communication networks may be configured to perform operations relating to the example LPL mode techniques provided below in connection with FIGS.

[0027] Each element in FIG. 1 can be considered a node in the wireless communication system 100. Details regarding possible implementations of a node are exemplarily provided in the description of the node 200 in FIG. 2. The node 200 may be configured as the UE 120, the AP 140, or the server 150 in FIG. 1. As shown in FIG. 2, the node 200 may include a processor 202, a memory 204, and a transceiver 206. While these components are shown connected to each other by a bus, other connection types are also permissible. If the node 200 is a UE 120, it may further include additional components such as a user interface (UI), sensors, etc. Similarly, if the node 200 is configured as the server 150, the node 200 may be implemented as a blade in a server system. Other implementations are also possible.

[0028] The transceiver 206 may include any suitable device for transmitting and / or receiving data. The node 200 may include one or more transceivers, although only one transceiver 206 is shown for simplicity of explanation. The antenna 208 is shown as a possible communication mechanism for the node 200. Multiple antennas and / or antenna arrays may be utilized to receive multiple spatially multiplexed data streams. Also illustratively, the node 200 may communicate using wired technology rather than (or in addition to) wireless technology. For example, the AP 140 may communicate wirelessly with the UE 120 and may communicate with the server 150 via a wired connection (e.g., optical or coaxial cable). Additionally, other communication hardware, such as a network interface card (NIC), may be included.

[0029] As shown in FIG. 2, node 200 may include a processor 202. While only one processor is shown, it is understood that multiple processors may be included. Processor 202 may include microprocessors, microcontroller units (MCUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform various functions described throughout the present invention. Processor 202 may be a hardware device having one or more processing cores. Processor 202 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software may include computer instructions written in interpreted language, compiled language, or machine code. Other techniques for referring to hardware are also recognized within the broad category of software.

[0030] As shown in FIG. 2 , node 200 may further include memory 204. While only one memory is shown, it is understood that multiple memories may be included. Memory 204 may broadly include both memory and storage. For example, memory 204 may include random-access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferroelectric RAM (FRAM), electrically erasable programmable ROM (EEPROM), compact disc read only memory (CD-ROM) or other optical disk storage, hard disk drive (HDD) (e.g., magnetic disk storage or other magnetic storage device), flash drive, solid-state drive (SSD), or any other medium usable to carry or store desired program code in the form of instructions, which can be accessed and executed by processor 202. In broad terms, memory 204 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0031] The processor 202, memory 204, and transceiver 206 may be implemented in various ways in node 200 and are configured to perform wireless communication functions. In some embodiments, the processor 202, memory 204, and transceiver 206 of node 200 are implemented (e.g., integrated) on one or more system-on-chip (SOC). In one example, the processor 202 and memory 204 may be integrated on an application processor (AP) SoC (sometimes referred to as a “host” and herein as a “host chip”), where the AP SoC handles application processing in an operating system (OS) environment, including generation of the original data to be transmitted. In another example, the processor 202 and memory 204 may be integrated on a baseband processor (BP) SoC (sometimes called a “modem” and referred to herein as a “radio”), which may, for example, convert original data from a host chip into signals that can be used to modulate a carrier frequency for transmission, and vice versa, and may run a real-time operating system (RTOS). In yet another example, the processor 202 and the transceiver 206 (and possibly further including the memory 204) may be integrated on an RF SoC (sometimes called a “transceiver” and referred to herein as a “wireless network interface”), which transmits and receives RF signals using the antenna 208. It should be understood that in some examples, some or all of the host chip, the radio, and the wireless network interface may be integrated into a single SoC. For example, the radio and the wireless network interface may be integrated into a single SoC, which manages all radio functions used for GNSS communication, WLAN communication, WPAN communication, and / or cellular communication.

[0032] 3 is a block diagram of an apparatus 300 including a wireless receiver 302, a wireless network interface 304, and a host chip 306, in accordance with some embodiments of the present invention. The apparatus 300 may be implemented as a UE 120 of the wireless communication system 100 of FIG. 1. In some embodiments, the wireless receiver 302 is implemented by the processor 202 and memory 204, and the wireless network interface 304 is implemented by the processor 202, memory 204, and transceiver 206 described above with respect to FIG. 2.

[0033] In addition to on-chip memory 318 (also referred to as “internal memory,” e.g., registers, buffers, or cache) on the wireless receiver 302, wireless network interface 304, or host chip 306, the device 300 may further include external memory 308 (e.g., system memory or main memory), which may be shared by the wireless receiver 302, wireless network interface 304, or host chip 306 via a system / main bus. While the wireless receiver 302 is illustrated in FIG. 3 as a standalone SoC, it should be understood that in one example, the wireless receiver 302 and wireless network interface 304 may be integrated into a single SoC. In another example, the wireless receiver 302 and host chip 306 may be integrated into a single SoC. In yet another example, as discussed above, the wireless receiver 302, wireless network interface 304, and host chip 306 may be integrated into a single SoC.

[0034] When the device 300 is a non-AP STA in the uplink, and when the device is an AP in the downlink, the host chip 306 can generate original data and send it to the wireless receiver 302 for encoding, modulation, and mapping. The interface 314 of the wireless receiver 302 can receive data from the host chip 306. The wireless receiver 302 can also access original data generated by the host chip 306 and stored in the external memory 308, for example, using direct memory access (DMA). The wireless receiver 302 can first encode the original data (e.g., by source coding and / or channel coding) and modulate the encoded data using any suitable modulation technique, such as multi-phase shift keying (MPSK) modulation or quadrature amplitude modulation (QAM). The wireless receiver 302 can perform any other functions, such as symbol or layer mapping, to convert the original data into a signal that can be used to modulate a carrier frequency for transmission. In the uplink, the wireless receiver 302 can transmit modulated signals to the wireless network interface 304 via interface 314. The wireless network interface 304 can convert the digitally modulated signals to analog, i.e., RF, signals via a transmitter (TX) 350 and can perform any suitable front-end RF functions, such as filtering, digital pre-distortion, up-conversion, or sample rate conversion. The antenna array 310 can transmit the RF signals provided by the TX 350 of the wireless network interface 304.

[0035] For example, on the downlink when device 300 is a non-AP STA and on the uplink when device 300 is an AP, antenna array 310 may receive one or more signals from an AP. The signals may be passed to a receiver (RX) 340 of wireless network interface 304. Wireless network interface 304 may perform any suitable front-end RF functions, such as filtering, IQ imbalance compensation, down-paging conversion, or sample rate conversion, to convert the RF signals (e.g., transmissions) into low-frequency digital signals (baseband signals) that can be processed by wireless receiver 302.

[0036] As shown in FIG. 3, the wireless receiver 302 may include, for example, an LPL mode component 320 and an active mode component 322. When in the LPL mode, the LPL mode component 320 is activated, and the active mode component 322 may enter a sleep mode to conserve power. When in the active mode, the active mode component 322 is active, and the LPL mode component 320 may enter a sleep mode to conserve power. Additional details related to the LPL mode and its example operations are described below in conjunction with FIGs. 4A-4D. When the device 300 is implemented as a non-AP STA, the wireless receiver 302 may perform operations 401, 403, 411, 413, 415, 417, 425, 427, 433, 435, 451, 453, 455, and 465 of FIGs. 4A-4D. On the other hand, if device 300 is implemented as an AP, wireless receiver 302 may perform operations 405, 407, 409, 419, 421, 423, 429, 431, 437, 439, 457, 459, 461, 463, and 465 of Figures 4A-4C. Optional operations are indicated by dashed lines in Figures 4A-4C.

[0037] 4A-4C illustrate a call flow diagram of a first exemplary LPL operation 400 between a first node 402 (e.g., a non-AP STA) and a second node 404 (e.g., an AP) in accordance with some embodiments of the present invention. FIG. 4D illustrates a call flow diagram of a second exemplary LPL operation 450 between a first node 402 and a second node 404 in accordance with some embodiments of the present invention. FIG. 5 illustrates an exemplary LPL frame 500 including multiple subfields in accordance with some embodiments of the present invention. FIG. 6 illustrates an exemplary timing diagram 600 of an LPL mode period and an active mode period in accordance with some embodiments of the present invention. FIG. 7 illustrates an exemplary EMLSR linkset in accordance with some embodiments of the present invention. FIG. 8 illustrates an exemplary EMLSR bitmap subfield 800 in an EML frame in accordance with some embodiments of the present invention. FIG. 9 illustrates an exemplary MLD linkset in accordance with some embodiments of the present invention. FIGS. 4A-4C, 5, and 6 are discussed collectively, and FIGS. 4D and 7-9 are discussed collectively.

[0038] 4A, 5, and 6, a first node 402 (e.g., a non-AP STA) may generate a first LPL frame (operation 401) having an LPL subfield 502 set to "enable." For example, the first node 402 may include a first bit value (e.g., 1) in the LPL subfield 502 to enable the LPL mode. The first node 402 may also generate a first LPL frame (operation 401) by setting a bit value in a supported-BW subfield 504 to indicate a maximum BW that the first node 402 supports in the LPL mode. For example, the first node 402 may set a first bit value (e.g., 00) to indicate a first maximum BW (e.g., 20 MHz) and a second bit value (e.g., 01) to indicate a second maximum BW (e.g., 80 MHz). Additionally, the first node 402 may set a first bit value in the supported-MCS subfield 506 to indicate the maximum MCS (or data rate) it supports while in LPL mode. The candidate MCSs may include, for example, binary phase-shift keying (BPSK) or quadrature phase-shift keying (QPSK). The candidate data rates may include 6 Mbps, 12 Mbps, 24 Mbps, etc. The padding-duration subfield 508 may be used by the second node to indicate the minimum padding duration required for an active frame. Referring to FIG. 6, the active frame is a multi-user (MU) request-to-send (RTS) (MU-RTS) frame 601a and includes a requested padding duration 601b. In the non-limiting example shown in FIG. 6, the padding duration is 150 μs.The padding duration 601b may be less than 150 μs or greater than 150 μs (e.g., 16 μs, 32 μs, 64 μs, 128 μs, 150 μs, 256 μs, etc.) without departing from the scope of the present invention. The padding duration 601b may be calculated from the end of the last orthogonal frequency division multiplexing (OFDM) symbol carrying user-specific information to the end of the physical layer protocol data unit (PPDU) 605 transmitted during the active period 620. The transition-duration subfield 510 may be set to indicate the minimum transition duration 609 required for the first node 402 to transition from the active mode to the LPL mode. The padding duration 601b may be selected to allow the first node 402 to transition from the LPL mode to the active mode.

[0039] Referring again to FIG. 4A , once the first LPL frame is generated, the first node 402 may transmit the first LPL frame to the second node 404 (operation 403). The second node 404 may identify that the LPL subfield 502 is set to “enable” (operation 405) and generate a second LPL frame with the LPL subfield set to “enable” (operation 407). The second node 404 may then transmit the second LPL frame to the first node 402 (at operation 409). The first node 402 may identify that the LPL subfield in the second LPL frame is set to “enable” (operation 411). The first node 402 may enable LPL mode (operation 413). In some embodiments, in response to transmitting the first LPL frame (operation 403), the first node 402 may enable LPL mode (operation 413). In some alternative embodiments, in response to identifying the LPL subfield in the second LPL frame as being set to “enabled” (operation 411), the first node 402 may enable the LPL mode (operation 413).

[0040] Referring to FIG. 4B , to tear down the LPL mode, the first node 402 may generate a third LPL frame having the LPL subfield 502 set to “disable” (operation 415). Other subfields in the third LPL frame may remain the same as the subfields in the first LPL frame. The first node 402 may then transmit the third LPL frame to the second node 404 (operation 417). The second node 404 may identify that the LPL subfield in the third LPL frame is set to “disable” (operation 419) and generate a fourth LPL frame having the LPL subfield set to “disable” (operation 421). The second node 404 may transmit the fourth LPL frame to the first node 402 (operation 423). The first node 402 may identify that the LPL subfield in the fourth LPL frame is set to “disable” (operation 425). The first node 402 may disable the LPL mode (operation 427). In some embodiments, in response to transmitting the third LPL frame (operation 417), the first node 402 may disable the LPL mode (operation 427). In some other embodiments, in response to identifying that the LPL subfield in the fourth LPL frame is set to “disable” (operation 425), the first node 402 may disable the LPL mode (operation 427).

[0041] Referring to FIG. 4C , to transition the first node 402 to active mode without exiting LPL mode, the second node 404 may generate an active frame (operation 429). The active frame may be generated based on information included in the padding duration subfield 508 in the first LPL frame. Referring to FIG. 6 , as described above, the active frame may include an MU-RTS frame 601a having a padding duration 601b. The second node 404 may transmit the active frame to the first node 402 (operation 431). The first node 402 may generate a second active frame (operation 433) and transmit the second active frame to the second node 404 (operation 435). The second active frame may include a clear-to-send (CTS) frame 603, as shown in FIG. 6 .

[0042] Referring to FIG. 6, after transmitting CTS 603, the first node 402 enters an active mode (e.g., a high-power mode) and performs a frame exchange with a higher MCS, a greater data throughput, and / or a greater BW. During an active period 620, the second node 404 may generate (operation 437) an active mode frame, such as a physical layer protocol data unit (PPDU) 605 of FIG. 6. The second node 404 may transmit (operation 439) the active mode frame to the first node 402 with a higher MCS, a greater throughput, and / or a greater bandwidth than the communication transmitted during the LPL period 610. Continuing with reference to FIG. 6, the first node 402 may indicate receipt of the active mode frame by transmitting a block acknowledgement (BA) 607. The first node 402 may then transition to LPL mode during the minimum transition duration 609 of the next LPL period 610.

[0043] In some embodiments, the active mode frame exchange may end, for example, when 1) the second node 404's transmission opportunity ends, or 2) the first node 402 does not receive a packet after transmitting the CTS frame 603. Other operations that may be performed during the active period 620 include, for example, 1) a sounding process (trigger-based and non-trigger-based sounding), 2) uplink transmissions of the first node 402, etc.

[0044] 4D, 7, and 8, the present invention provides exemplary EMLSR operations by which a first node 402 (e.g., a non-AP multi-link device (MLD)) having multiple receive chains can monitor one or more EMLSR links when a second node 404 (e.g., one or more corresponding Non-AP STAs) belonging to the non-AP MLD is in an awake state. The one or more EMLSR links can be indicated by the first node 402. Once the indication is received, the second node 404 can transmit an initial control frame, sent in a PPDU (e.g., a non-high-throughput (non-HT) PPDU), indicating which of the one or more EMLSR links will be used for frame exchange based on the received link initial control frame.

[0045] For example, the first node 402 may identify (operation 451) a first EMLSR link set (one or more EMLSR links). Although not shown, in some embodiments, the first EMLSR link set 702 may include only a single link. As shown in FIG. 7, in some embodiments, the first EMLSR link set 702 may include a first low-power link (Link 0) and a first high-power link (Link 1). As used herein, "EMLSR link set" may include, for example, a null set, a single EMLSR link, two EMLSR links, three EMLSR links, etc.

[0046] 4D, 7, and 8, the first node 402 may identify (operation 453) a second EMLSR link set (one or more EMLSR links). Although not shown, in some embodiments, the first EMLSR link set 702 may include only a single link. As shown in FIG. 7, the second EMLSR link set 704 may include a second low-power link (Link 2) and a second high-power link (Link 2).

[0047] 4D, 7, and 8, the first node 402 may send (operation 455) a first indication of a first EMLSR linkset 702, or a first EMLSR linkset 702 and a second EMLSR linkset 704. Referring to FIG. 8, the present invention enables an indication of the first EMLSR linkset 702, or an indication of the first EMLSR linkset 702 and a second EMLSR linkset 704, in an EMLSR link bitmap subfield 800. For example, the EML control field (not shown) may be modified to include a "Number of EMLSR links" subfield 802, which may indicate that multiple EMLSR links are established for a non-AP MLD (e.g., the first node 402). Each EMLSR linkset includes one or more links indicated by subfields, e.g., EMLSR link bitmap 804a for the first linkset (links_1), EMLSR link bitmap 804b for the second linkset (links_2), ..., EMLSR link bitmap 804n for the nth linkset (links_n), where n represents the total number of EMLSR linksets indicated by the EMLSR link count subfield 802. In this embodiment, the first node 402 can generate a frame with an EMLSR link bitmap subfield 800 (first indication) indicating the first EMLSR linkset 702 and the second EMLSR linkset 704.

[0048] 8, the first node 402 may indicate one or more EMLSR links in the EMLSR Link Bitmap subfield 800 of the EML Control field of the EML operational mode notification frame by setting to one one or more bit positions corresponding to the link identification (ID) values ​​of the one or more EMLSR links in the EMLSR Link Bitmap subfield 800. In some embodiments, the first node 402 may set to one only one bit in the bit positions of the EMLSR Link Bitmap subfield 800 when enabling EMLSR mode, which may be the case if the EMLSR link set contains only a single EMLSR link. In an EMLSR mode enabled in a single-radio non-AP MLD (e.g., one embodiment of the first node 402), when a non-AP STA operating on one or more EMLSR links belonging to the non-AP MLD is in an awake state, one or more STAs operating on one or more enabled links for which one or more bit positions of the EMLSR link bitmap subfield 800 are 0 can operate in LPL mode or sleep mode.

[0049] The second node 404 may identify (operation 457) one or more EMLSR links in each set based on the information in the EMLSR link bitmap subfield 800. The second node 404 may select (operation 459) a first EMLSR link from the first EMLSR link set 702, or select a first EMLSR link from the first EMLSR link set 702 and a second EMLSR link from the second EMLSR link set 704. The second node 404 may generate (at operation 461) a second indication for the selected one or more EMLSR links.

[0050] The second node 404 may send a second indication for the selected one or more EMLSR links (operation 463). The first node 402 and the second node 404 may perform packet switching using the one or more EMLSR links during the LPL mode and the active mode (operation 465). The packet switching may include monitoring the selected one or more EMLSR links. If two links are indicated, simultaneous Tx / Rx operation may be performed during the LPL mode and / or the active mode.

[0051] Referring to FIG. 9, another alternative solution to solving the above EMLSR problem is to allow the first node 402 (e.g., MLD) to establish multiple sub-MLDs. Each sub-MLD reuses the existing EMLSR definition and operation process. In the example shown in FIG. 9, the first node 402 can establish two sub-non-AP MLDs; that is, the first node 402 can consider itself as two non-AP MLDs. For example, sub-non-AP MLD 1 is associated with link 0 and link 1, and link 0 and link 1 form a first EMLSR link set 902 of the sub-non-AP MLD 1. Sub-non-AP MLD 2 is associated with link 2 and link 3, and link 2 and link 3 form a second EMLSR link set 904 of the sub-non-AP MLD 2. In this example, the first node 402 may associate the first subMLD with the first EMLSR linkset 902 and the second subMLD with the second EMLSR linkset 904 (operation 455).

[0052] 10A and 10B are flowcharts of a first exemplary wireless communication method 1000 according to an embodiment of the present invention. The first method 1000 may be performed by a wireless device such as a UE 120, a node 200, an apparatus 300, a wireless receiver 302, an LPL mode component 320, an active mode component 322, a first node 402, or a non-AP STA. The first method 1000 may include the following steps 1002 to 1028. It should be understood that some steps are optional, and some steps may be performed simultaneously or in a different order than that shown in FIGS. 10A and 10B.

[0053] 10A, in step 1002, a wireless device may generate a first LPL frame having a first LPL subfield set to "enable." For example, referring to FIG. 4A, a first node 402 (e.g., a non-AP STA) may generate a first LPL frame having an LPL subfield 502 set to "enable" (operation 401). For example, the first node 402 may include a first bit value (e.g., 1) in the LPL subfield 502 to enable the LPL mode. The first node 402 may also generate the first LPL frame (operation 401) by setting a bit value in the supported BW subfield 504 to indicate a maximum BW that the first node 402 supports in the LPL mode. For example, the first node 402 may set a first bit value (e.g., 00) to indicate a first maximum BW (e.g., 20 MHz) and a second bit value (e.g., 01) to indicate a second maximum BW (e.g., 80 MHz). Additionally, the first node 402 may set a first bit value in the supported MCS subfield 506 to indicate the maximum MCS (or data rate) it supports while in LPL mode. The candidate MCSs may include, for example, binary phase-shift keying (BPSK) or quadrature phase-shift keying (QPSK). The candidate data rates may include 6 Mbps, 12 Mbps, 24 Mbps, etc. The padding duration subfield 508 may be used by the second node to indicate the minimum padding duration required for an active frame. Referring to FIG. 6, the active frame is a multi-user (MU) request-to-send (RTS) (MU-RTS) frame 601a and includes a requested padding duration 601b. In the non-limiting example shown in FIG. 6, the padding duration is 150 μs. The padding duration 601b may be less than 150 μs or greater than 150 μs (eg, 16 μs, 32 μs, 64 μs, 128 μs, 150 μs, 256 μs, etc.) without departing from the scope of the present invention.The padding duration 601b may be calculated from the end of the last orthogonal frequency division multiplexing (OFDM) symbol carrying user-specific information to the end of the physical layer protocol data unit (PPDU) 605 transmitted during the active period 620. The transition duration subfield 510 may be set to indicate the minimum transition duration 609 required for the first node 402 to transition from the active mode to the LPL mode.

[0054] In step 1004, the wireless device may transmit a first LPL frame to the second node with the first LPL subfield set to “enabled.” For example, with reference to FIG. 4A, once the first LPL frame is generated, the first node 402 may transmit the first LPL frame to the second node 404 (operation 403).

[0055] After transmitting the first LPL frame with the first LPL subfield set to “enable” to the second node in step 1006, the wireless device may enable the LPL mode. For example, with reference to FIG. 4A , the first node 402 may enable the LPL mode (operation 413). In some embodiments, in response to transmitting the first LPL frame (operation 403), the first node 402 may enable the LPL mode (operation 413). In some other embodiments, in response to identifying that the LPL subfield in the second LPL frame is set to “enable” (operation 411), the first node 402 may enable the LPL mode (at operation 413).

[0056] In step 1008, the wireless device may receive a second LPL frame from the second node having the second LPL subfield set to “enabled.” For example, with reference to FIG. 4A, the second node 404 may transmit a second LPL frame (operation 409), which is received by the first node 402.

[0057] In step 1010, the wireless device may identify that the second LPL subfield in the second LPL frame received from the second node is set to “enable.” For example, referring to FIG. 4A, the first node 402 may identify that the LPL subfield in the second LPL frame is set to “enable” (operation 411).

[0058] In step 1012, the wireless device may generate a second LPL frame with the second LPL subfield set to "disabled." For example, referring to FIG. 4B, to exit LPL mode, the first node 402 may generate (operation 415) a third LPL frame with the LPL subfield 502 set to "disabled." The other subfields in the third LPL frame may remain the same as the subfields in the first LPL frame.

[0059] In step 1014, the wireless device may transmit a second LPL frame to the second node with the second LPL subfield set to “disabled.” For example, referring to FIG. 4B, the first node 402 may transmit a third LPL frame to the second node 404 (operation 417).

[0060] 10B, after transmitting the second LPL frame with the second LPL subfield set to "disable" to the second node in step 1016, the wireless device may disable the LPL mode. For example, referring to FIG. 4B, the first node 402 may disable the LPL mode (operation 427). In some embodiments, in response to transmitting the third LPL frame (operation 417), the first node 402 may disable the LPL mode (operation 427). In some other embodiments, in response to identifying that the LPL subfield in the fourth LPL frame is set to "disable" (operation 425), the first node 402 may disable the LPL mode (operation 427).

[0061] In step 1018, the wireless device may receive from the second node a third LPL frame with the third LPL subfield set to “disabled.” For example, referring to FIG. 4B, the second node 404 may transmit a fourth LPL frame (operation 423), which is received by the first node 402.

[0062] In step 1020, the wireless device may identify that the third LPL subfield in the second LPL frame received from the second node is set to “disabled.” For example, with reference to FIG. 4C, the first node 402 may identify that the LPL subfield in the fourth LPL frame is set to “disabled” (operation 425).

[0063] In step 1022, the wireless device may receive a first active frame from the second node during the LPL mode period. For example, referring to Figure 4C, the second node 404 may transmit an active frame (operation 431), which is received by the first node 402.

[0064] In step 1024, the wireless device may generate a second active frame associated with the active mode communication. For example, with reference to Figure 4C, the first node 402 may generate a second active frame (operation 433).

[0065] In step 1026, the wireless device may transmit a second active frame to the second node at the start of an active mode period. For example, referring to Figure 4C, the first node 402 may transmit a second active frame to the second node 404 (operation 435). As shown in Figure 6, the second active frame may include a CTS frame 603.

[0066] In step 1028, the wireless device may receive an active mode frame from the second node during an active mode period. For example, referring to FIG. 4C , the second node 404 may transmit (operation 439) an active mode frame to the first node 402 with a larger MCS, a larger throughput, and / or a larger bandwidth than the communication transmitted during the LPL period 610. The first node 402 may receive the active mode frame.

[0067] 11 is a flowchart of a second exemplary wireless communication method 1100 according to an embodiment of the present invention. The second method 1100 is performed by a wireless device, such as a UE 120, a node 200, an apparatus 300, a wireless receiver 302, an LPL mode component 320, an active mode component 322, a first node 402, or a non-AP STA. The second method 1100 may include the following steps 1102 to 1110. It should be understood that some steps are optional, and some steps may be performed simultaneously or in a different order than that shown in FIG. 11.

[0068] 11, in step 1102, the wireless device may identify a first EMLSR link set associated with the LPL mode and the active mode. For example, referring to FIG. 4D, the first node 402 may identify (operation 451) a first EMLSR link set (one or more EMLSR links). Although not shown, in some embodiments, the first EMLSR link set 702 may include only a single link. As shown in FIG. 7, in some embodiments, the first EMLSR link set 702 may include a first low-power link (Link 0) and a first high-power link (Link 1).

[0069] In step 1104, the wireless device may identify a second EMLSR link set associated with the LPL mode and the active mode. For example, referring to FIG. 4D , the first node 402 may identify (operation 453) a second EMLSR link set (one or more EMLSR links). Although not shown, in some embodiments, the first EMLSR link set 702 may include only a single link. As shown in FIG. 7, the second EMLSR link set 704 may include a second low-power link (Link 2) and a second high-power link (Link 2).

[0070] In step 1106, the wireless device may transmit a first indication of a first EMLSR linkset, or the first EMLSR linkset and a second EMLSR linkset. For example, referring to FIG. 4D, the first node 402 may transmit (operation 455) a first indication of a first EMLSR linkset 702, or the first EMLSR linkset 702 and a second EMLSR linkset 704. Referring to FIG. 8, the present invention enables an indication of the first EMLSR linkset 702, or the first EMLSR linkset 702 and the second EMLSR linkset 704, in an EMLSR link bitmap subfield 800. For example, the EML control field (not shown) may be modified to include a "Number of EMLSR Links" subfield 802, which may indicate that multiple EMLSR links are established for a non-AP MLD (e.g., the first node 402). Each EMLSR link set includes one or more links indicated by subfields, e.g., EMLSR link bitmap for links_1 804a, EMLSR link bitmap for links_2 804b, ..., EMLSR link bitmap for links_n 804n, where n represents the total number of EMLSR link sets indicated by the EMLSR link count subfield 802. In this embodiment, the first node 402 can generate a frame with an EMLSR link bitmap subfield 800 (first indication) indicating the first EMLSR link set 702 and the second EMLSR link set 704.

[0071] In step 1108, the wireless device may receive a second indication for a first link from the first EMLSR linkset, or an indication for a first link from the first EMLSR linkset and a second link from the second EMLSR linkset. For example, referring to FIG. 4D , if multiple links are indicated, the second node 404 may select (operation 459) a first EMLSR link from the first EMLSR linkset 702, or select a first EMLSR link from the first EMLSR linkset 702 and a second EMLSR link from the second EMLSR linkset 704. The second node 404 may send (operation 463) a second indication for the selected one or more EMLSR links, which is received by the first node 402.

[0072] In step 1110, the wireless device may perform packet exchange with the second node using the first link, or using the first link and the second link. For example, referring to Figure 4D, the first node 402 and the second node 404 may perform packet exchange (operation 465) using the EMLSR link during the LPL mode and the active mode. If two links are shown, simultaneous Tx / Rx operation may be performed during the LPL mode and / or the active mode.

[0073] 12A and 12B are flowcharts of a third exemplary wireless communication method 1200 according to an embodiment of the present invention. The third method 1200 may be performed by a wireless device, such as an AP 140, a node 200, an apparatus 300, a wireless receiver 302, an LPL mode component 320, an active mode component 322, a second node 404, or an AP STA. The third method 1200 may include the following steps 1202 to 1226. It should be understood that some steps are optional, and some steps may be performed simultaneously or in a different order than that shown in FIGS. 12A and 12B.

[0074] 12A, in operation 1202, a wireless device may receive a first LPL frame from a second node having a first LPL subfield set to “enabled.” For example, referring to FIG. 4A, a first node 402 may transmit a first LPL frame (operation 403), which is received by a second node 404.

[0075] In step 1204, the wireless device may identify that the first LPL subfield in the first LPL frame is set to “enable.” For example, referring to FIG. 4A, the second node 404 may identify (operation 405) that the LPL subfield 502 is set to “enable.”

[0076] In step 1206, the wireless device may generate a second LPL frame with the second LPL subfield set to “enabled.” For example, referring to FIG. 4A, the second node 404 may generate a second LPL frame with the LPL subfield set to “enabled” (operation 407).

[0077] In step 1208, the wireless device may transmit a second LPL frame to the second node with the second LPL subfield set to “enabled.” For example, with reference to FIG. 4A, the second node 404 may transmit a second LPL frame to the first node 402 (operation 409).

[0078] In step 1210, the wireless device may receive a second LPL frame with the second LPL subfield set to “disabled.” For example, with reference to FIG. 4B, the first node 402 may transmit a third LPL frame (operation 417), which is received by the second node 404.

[0079] In step 1212, the wireless device may identify that the second LPL subfield in the second LPL frame is set to “disabled.” For example, referring to FIG. 4B, the second node 404 may identify that the LPL subfield in the third LPL frame is set to “disabled” (operation 419).

[0080] In step 1214, the wireless device may generate a third LPL frame with the third LPL subfield set to "disabled." For example, with reference to FIG. 4B, the second node 404 may generate a fourth LPL frame (operation 421) with the LPL subfield set to "disabled."

[0081] 12B, in step 1216, the wireless device may transmit a third LPL frame to the second node with the third LPL subfield set to "disabled." For example, referring to FIG. 4B, the second node 404 may transmit a fourth LPL frame to the first node 402 (operation 423).

[0082] In step 1218, the wireless device may generate a first active frame indicating a transition from LPL mode to active mode. For example, referring to FIG. 4C, to transition the first node 402 to active mode without exiting LPL mode, the second node 404 may generate an active frame (operation 429). The active frame may be generated based on information included in the padding duration subfield 508 in the first LPL frame. Referring to FIG. 6, as previously described, the active frame may include an MU-RTS frame 601a having a padding duration 601b.

[0083] In step 1220, the wireless device may transmit a first active frame to the second node during the LPL mode period. For example, with reference to Figure 4C, the second node 404 may transmit an active frame to the first node 402 (operation 431).

[0084] In step 1222, the wireless device may receive a second active frame transmitted from the second node at the start of an active mode period. For example, with reference to Figure 4C, the first node 402 may transmit a second active frame (operation 435), which is received by the second node 404.

[0085] In step 1224, the wireless device may generate an active mode frame. For example, referring to Figure 4C, during the active period 620, the second node 404 may generate (operation 437) an active mode frame, such as physical layer protocol data unit (PPDU) 605 of Figure 6.

[0086] In step 1226, the wireless device may transmit an active mode frame to the second node during an active mode period. For example, referring to FIG. 4C , the second node 404 may transmit (operation 439) an active mode frame to the first node 402 with a larger MCS, a larger throughput, and / or a larger bandwidth than the communication transmitted during the LPL period 610.

[0087] 13 is a flowchart of a fourth exemplary wireless communication method 1300 according to an embodiment of the present invention. The fourth method 1300 may be performed by a wireless device such as an AP 140, a node 200, an apparatus 300, a wireless receiver 302, an LPL mode component 320, an active mode component 322, a second node 404, or an AP STA. The fourth method 1300 may include the following steps 1302 to 1312. It should be understood that some steps are optional, and some steps may be performed simultaneously or in a different order than that shown in FIG. 13.

[0088] Referring to FIG. 13, in step 1302, the wireless device may receive from the second node a first indication of one or more EMLSR link sets associated with the LPL mode and the active mode. For example, referring to FIG. 4D, the first node 402 may send (operation 455) a first indication of the first EMLSR link set 702, or the first EMLSR link set 702 and the second EMLSR link set 704, which is received by the second node. Referring to FIG. 8, the present invention enables an indication of the first EMLSR link set 702, or the first EMLSR link set 702 and the second EMLSR link set 704, in an EMLSR link bitmap subfield 800. For example, the EML control field (not shown) may be modified to include a “number of EMLSR links” subfield 802, which may indicate that multiple EMLSR links are established for a non-AP MLD (e.g., the first node 402). Each EMLSR link set includes one or more links indicated by subfields, e.g., EMLSR link bitmap for links_1 804a, EMLSR link bitmap for links_2 804b, ..., EMLSR link bitmap for links_n 804n, where n represents the total number of EMLSR link sets indicated by the EMLSR link count subfield 802. In this embodiment, the first node 402 can generate a frame with an EMLSR link bitmap subfield 800 (first indication) indicating the first EMLSR link set 702 and the second EMLSR link set 704.

[0089] In step 1304, the wireless device may identify one or more EMLSR link sets associated with the LPL mode and the active mode based on the first indication. For example, referring to FIG. 4D , the second node 404 may identify (operation 457) one or more EMLSR links in each set based on information in the EMLSR link bitmap subfield 800.

[0090] In step 1306, the wireless device may select a first EMLSR link from the first EMLSR linkset, or select a first EMLSR link from the first EMLSR linkset and select a second EMLSR link from the second EMLSR linkset. For example, referring to Figure 4D, the second node 404 may select (operation 459) a first EMLSR link from the first EMLSR linkset 702, or select a first EMLSR link from the first EMLSR linkset 702 and select a second EMLSR link from the second EMLSR linkset 704.

[0091] In step 1308, the wireless device may generate a second indication for the first link from the first EMLSR link set, or a second indication for the first link from the first EMLSR link set and the second link from the second EMLSR link set. For example, referring to FIG. 4D , the second node 404 may generate (operation 461) a second indication for the selected one or more EMLSR links.

[0092] In step 1310, the wireless device may transmit a second instruction to the second node for the first EMLSR link from the first EMLSR link set, or for the first EMLSR link from the first EMLSR link set and the second EMLSR link from the second EMLSR link set. For example, referring to FIG. 4D , the second node 404 may transmit (operation 463) the second instruction for the selected one or more EMLSR links.

[0093] In step 1312, the wireless device may perform a packet exchange with the second node using the first link, or using the first link and the second link. For example, referring to FIG. 4D , the first node 402 and the second node 404 may perform a packet exchange (operation 465) using one or more EMLSR links during the LPL mode and the active mode. The packet exchange may include monitoring the selected one or more EMLSR links.

[0094] In various aspects of the present invention, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored or encoded as instructions or code on a non-transitory computer-readable medium. Computer-readable media include computer storage media. A storage medium may be any available medium accessible by a computing device, such as node 200 of FIG. 2. By way of non-limiting example, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, HDD (magnetic disk storage or other magnetic storage), flash drive, SSD, or any other medium. The medium may be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a processing system (such as a mobile device or computer). As used herein, disk and disc include CDs, laser discs, optical discs, digital video discs (DVDs), and floppy disks, where disks typically reproduce data magnetically and discs typically reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0095] According to one aspect of the present invention, there is provided a wireless communication method for a first node. The wireless communication method may include generating, by at least one processor, a first LPL frame having a first LPL subfield set to "enabled." The wireless communication method may include transmitting, by a communication interface, the first LPL frame having the first LPL subfield set to "enabled" to a second node. The wireless communication method may include enabling, by the at least one processor, an LPL mode after transmitting the first LPL frame having the first LPL subfield set to "enabled" to the second node.

[0096] In some embodiments, the wireless communication method may include receiving, by the communication interface, a second LPL frame from the second node, the second LPL subfield being set to “enabled.” In some embodiments, the wireless communication method may include identifying, by the at least one processor, that the second LPL subfield in the second LPL frame received from the second node is set to “enabled.” In some embodiments, enabling the LPL mode by the at least one processor after transmitting a first LPL frame having a first LPL subfield set to “enabled” to the second node may include enabling the LPL mode in response to transmitting a first LPL frame having a first LPL subfield set to “enabled” to the second node. In some embodiments, enabling the LPL mode by the at least one processor after transmitting a first LPL frame having a first LPL subfield set to “enabled” to the second node may include enabling the LPL mode in response to identifying that the second LPL subfield in the second LPL frame received from the second node is set to “enabled.”

[0097] In some embodiments, the wireless communication method may include generating, by the at least one processor, a second LPL frame having a second LPL subfield set to “disabled.” In some embodiments, the wireless communication method may include transmitting, by the communication interface, the second LPL frame having the second LPL subfield set to “disabled” to the second node. In some embodiments, the wireless communication method may include enabling, by the at least one processor, the LPL mode after transmitting the second LPL frame having the second LPL subfield set to “disabled” to the second node.

[0098] In some embodiments, the wireless communication method may include receiving, by the communication interface, from the second node, a third LPL frame having a third LPL subfield set to “disabled.” In some embodiments, the wireless communication method may include identifying, by the at least one processor, that the third LPL subfield in the second LPL frame received from the second node is set to “disabled.” In some embodiments, disabling the LPL mode by the at least one processor after transmitting to the second node a second LPL frame having a second LPL subfield set to “disabled” may include disabling the LPL mode in response to transmitting to the second node a second LPL frame having a second LPL subfield set to “disabled.” In some embodiments, disabling the LPL mode by the at least one processor after transmitting a second LPL frame to the second node having a second LPL subfield set to “disabled” may include disabling the LPL mode in response to identifying that the third LPL subfield in the third LPL frame received from the second node is set to “disabled.”

[0099] In some embodiments, generating a first LPL frame having a first LPL subfield set to “enabled” by the at least one processor may include setting a supported BW subfield of the first LPL frame to indicate a maximum BW that the first node supports in LPL mode communication with the second node. In some embodiments, generating a first LPL frame having a first LPL subfield set to “enabled” by the at least one processor may include setting a supported MCS subfield of the first LPL frame to indicate a maximum MCS that the first node supports in LPL mode communication with the second node. In some embodiments, generating a first LPL frame having a first LPL subfield set to “enabled” by the at least one processor may include setting a padding subfield of the first LPL frame to indicate an amount of padding to be included in an active mode frame. In some examples, generating, by the at least one processor, a first LPL frame having a first LPL subfield set to “enabled” may include setting a transition duration subfield of the first LPL frame to indicate a duration associated with a transition of the first node from an active mode to an LPL mode.

[0100] In some embodiments, the wireless communication method may further include receiving, by the communication interface during an LPL mode period, a first active frame from the second node, the first active frame indicating a transition from the LPL mode to an active mode, the first active frame including a padding amount. In some embodiments, the first active frame may indicate a transition from the LPL mode to an active mode, the first active frame including a padding amount indicated in a padding subfield of the first LPL frame. In some embodiments, the wireless communication method may further include generating, by the at least one processor, a second active frame associated with active mode communication. In some embodiments, the wireless communication method may further include transmitting, by the communication interface, the second active frame to the second node at the start of an active mode period. In some embodiments, the wireless communication method may further include receiving, by the communication interface during the active mode period, an active mode frame from the second node.

[0101] In some embodiments, the first active frame may be an RTS frame, and in some embodiments, the second active frame may be a CTS frame.

[0102] According to another aspect of the present invention, there is provided a method of wireless communication for a first node, the method may include identifying, by at least one processor, a first EMLSR linkset associated with an LPL mode and an active mode, and transmitting, by a communication interface, a first indication of the first EMLSR linkset associated with an LPL mode and an active mode to the second node.

[0103] In some embodiments, the wireless communication method may include generating, by the at least one processor, a frame having an EMLSR link bitmap subfield, the EMLSR link bitmap subfield indicating a number of EMLSR links in the first EMLSR link set.

[0104] In some embodiments, the number of EMLSR links in the first EMLSR link set may include a single link, with only one bit set to one in the EMLSR Link Bitmap subfield.

[0105] In some embodiments, the number of EMLSR links in the first EMLSR link set may include a first EMLSR link and a second EMLSR link, and a number of bits are set to one in the EMLSR link bitmap subfield.

[0106] In some embodiments, the wireless communication method can include receiving, by the communication interface, a second indication indicating that the first EMLSR link is to be used for LPL mode communications and active mode communications.

[0107] In some embodiments, the wireless communication method may include monitoring, by the at least one processor, the first EMLSR link during the LPL mode and the active mode.

[0108] In some embodiments, the wireless communication method may further include identifying, by at least one processor, a second EMLSR linkset associated with an LPL mode and an active mode. In some embodiments, the first indication may include the first EMLSR linkset and the second EMLSR linkset.

[0109] In some embodiments, the wireless communication method may further include receiving, by the communication interface, a third instruction for a first EMLSR link of the first EMLSR link set and a second link of the second EMLSR link set, wherein the first EMLSR link and the second link are associated with simultaneous reception and simultaneous transmission.

[0110] According to yet another aspect of the present invention, there is provided a wireless communication device for a first node. The wireless communication device may include at least one processor. The wireless communication device may include a memory storing instructions. The instructions stored in the memory, when executed by the at least one processor, can cause the at least one processor to generate a first LPL frame having a first LPL subfield set to "enabled." The instructions stored in the memory, when executed by the at least one processor, can cause the at least one processor to transmit the first LPL frame having the first LPL subfield set to "enabled" to a second node. The instructions stored in the memory, when executed by the at least one processor, can cause the at least one processor to enable an LPL mode after transmitting the first LPL frame having the first LPL subfield set to "enabled" to the second node.

[0111] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to receive a second LPL frame from the second node having a second LPL subfield set to “enabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to identify that the second LPL subfield in the second LPL frame received from the second node is set to “enabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, to enter the LPL mode after transmitting a first LPL frame to the second node having a first LPL subfield set to “enabled” further cause the at least one processor to enable the LPL mode in response to transmitting a first LPL frame to the second node having a first LPL subfield set to “enabled.” In some embodiments, the instructions stored in the memory, when executed by the at least one processor for entering the LPL mode after transmitting a first LPL frame having a first LPL subfield set to “enable” to the second node, may further cause the at least one processor to enable the LPL mode in response to identifying that the second LPL subfield in the second LPL frame received from the second node is set to “enable.”

[0112] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to generate a second LPL frame having a second LPL subfield set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to transmit the second LPL frame having the second LPL subfield set to “disabled” to the second node. In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to disable the LPL mode after transmitting the second LPL frame having the second LPL subfield set to “disabled” to the second node.

[0113] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to receive from the second node a third LPL frame having a third LPL subfield set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to identify that the third LPL subfield in the second LPL frame received from the second node is set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, to disable the LPL mode after transmitting to the second node a second LPL frame having the second LPL subfield set to “disabled” further cause the at least one processor to disable the LPL mode in response to transmitting to the second node a second LPL frame having the second LPL subfield set to “disabled.” In some embodiments, the instructions stored in the memory, when executed by the at least one processor to disable the LPL mode after transmitting a second LPL frame to the second node having the second LPL subfield set to “disabled,” may further cause the at least one processor to disable the LPL mode in response to identifying that the third LPL subfield in the third LPL frame received from the second node is set to “disabled.”

[0114] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to set a Supported BW subfield of the first LPL frame to indicate a maximum BW the first node supports in LPL mode communication with the second node. In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to set a Supported MCS subfield of the first LPL frame to indicate a maximum MCS the first node supports in LPL mode communication with the second node. In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to set a Padding subfield of the first LPL frame to indicate an amount of padding to be included in an Active mode frame. In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to set a Transition Duration subfield of the first LPL frame to indicate a duration associated with a transition of the first node from an Active mode to an LPL mode.

[0115] In some embodiments, the instructions stored in memory, when executed by the at least one processor, can further cause the at least one processor to receive a first active frame from the second node during an LPL mode period. In some embodiments, the first active frame can indicate a transition from the LPL mode to an active mode, the first active frame including an amount of padding indicated in a padding subfield of the first LPL frame. In some embodiments, the instructions stored in memory, when executed by the at least one processor, can further cause the at least one processor to generate a second active frame associated with active mode communication. In some embodiments, the instructions stored in memory, when executed by the at least one processor, can further cause the at least one processor to transmit the second active frame to the second node at the start of an active mode period. In some embodiments, the instructions stored in memory, when executed by the at least one processor, can further cause the at least one processor to receive an active mode frame from the second node during the active mode period.

[0116] According to yet another aspect of the present invention, there is provided a wireless communication method for a first node, the wireless communication method may include receiving, via a communication interface, from a second node, a first LPL frame having a first LPL subfield set to “enabled,” and identifying, by at least one processor, that the first LPL subfield in the first LPL frame is set to “enabled.”

[0117] In some embodiments, the wireless communication method may include generating, by the at least one processor, a second LPL frame having a second LPL subfield set to “enabled.” In some embodiments, the wireless communication method may include transmitting, by the communication interface, the second LPL frame having the second LPL subfield set to “enabled” to the second node.

[0118] In some embodiments, the wireless communication method may include receiving, by the at least one processor, a second LPL frame having a second LPL subfield set to “disabled.” In some embodiments, the wireless communication method may include identifying, by the at least one processor, that the second LPL subfield in the second LPL frame is set to “disabled.” In some embodiments, the wireless communication method may include generating, by the at least one processor, a third LPL frame having a third LPL subfield set to “disabled.” In some embodiments, the wireless communication method may include transmitting, by the communication interface, a third LPL frame having a third LPL subfield set to “disabled” to the second node.

[0119] In some embodiments, the first LPL frame may further include a Supported BW subfield, where the Supported BW subfield indicates a maximum BW that the first node supports in LPL mode communication with the second node. In some embodiments, the first LPL frame may further include a Supported MCS subfield, where the Supported BW subfield indicates a maximum MCS that the first node supports in LPL mode communication with the second node. In some embodiments, a Padding subfield of the first LPL frame may indicate an amount of padding to be included in an Active mode frame. In some embodiments, a Transition Duration subfield of the first LPL frame may indicate a duration associated with a transition of the first node from Active mode to LPL mode.

[0120] In some embodiments, the wireless communication method may further include generating, by the at least one processor, a first active frame indicating a transition from the LPL mode to an active mode, the first active frame including a padding amount indicated in a padding subfield of the first LPL frame. In some embodiments, the wireless communication method may further include transmitting, by the at least one processor, the first active frame to a second node during an LPL mode period.

[0121] In some embodiments, the wireless communication method may further include receiving, by the communication interface, a second active frame from a second node at a start of an active mode period. In some embodiments, the wireless communication method may further include generating, by the at least one processor, an active mode frame. In some embodiments, the wireless communication method may further include transmitting, by the communication interface, the active mode frame to the second node during the active mode period.

[0122] In some embodiments, the first active frame may be an RTS frame, and in some embodiments, the second active frame may be a CTS frame.

[0123] According to yet another aspect of the present invention, there is provided a method of wireless communication for a first node, the method may include receiving, via a communication interface, from a second node a first indication of one or more EMLSR link sets associated with an LPL mode and an active mode, and identifying, by one or more processors, the one or more EMLSR link sets associated with the LPL mode and the active mode based on the first indication.

[0124] In some embodiments, the wireless communication method may further include one or more processors selecting a first EMLSR link from a first EMLSR linkset, or selecting a first EMLSR link from the first EMLSR linkset and a second EMLSR link from a second EMLSR linkset. In some embodiments, the wireless communication method may further include generating, by the one or more processors, a second indication for the first EMLSR link from the first EMLSR linkset, or a second indication for the first EMLSR link from the first EMLSR linkset and the second EMLSR link from the second EMLSR linkset. In some embodiments, the wireless communication method may further include transmitting, by a communication interface, the second indication for the first EMLSR link from the first EMLSR linkset, or the second indication for the first EMLSR link from the first EMLSR linkset and the second EMLSR link from the second EMLSR linkset to a second node.

[0125] In some embodiments, the number of EMLSR links in the first EMLSR link set may include a single link, with only one bit set to one in the EMLSR Link Bitmap subfield.

[0126] In some embodiments, the number of EMLSR links in the first EMLSR link set may include a first EMLSR link and a second EMLSR link, and a number of bits are set to one in the EMLSR link bitmap subfield.

[0127] In some embodiments, the wireless communication method may further include performing, by one or more processors, packet exchange with the second node using a first EMLSR link from the first EMLSR link set, or the first EMLSR link from the first EMLSR link set and a second EMLSR link from the second EMLSR link set.

[0128] According to yet another aspect of the present invention, there is provided a wireless communication device for a first node. The wireless communication device may include at least one processor. The wireless communication device may include a memory for storing instructions. The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to receive a first LPL frame from a second node, the first LPL frame having a first LPL subfield set to "enabled." The instructions stored in the memory, when executed by the at least one processor, cause the at least one processor to identify that the first LPL subfield in the first LPL frame is set to "enabled."

[0129] In some embodiments, the instructions stored in the memory, when executed by the at least one processor, further cause the at least one processor to generate a second LPL frame having a second LPL subfield set to “enabled.” In some embodiments, the instructions stored in the memory, when executed by the at least one processor, further cause the at least one processor to transmit a second LPL frame having the second LPL subfield set to “enabled” to the second node.

[0130] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to receive a second LPL frame having a second LPL subfield set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to identify that the second LPL subfield in the second LPL frame is set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to generate a third LPL frame having a third LPL subfield set to “disabled.” In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to transmit a third LPL frame having a third LPL subfield set to “disabled” to the second node.

[0131] In some embodiments, the first LPL frame may further include a Supported BW subfield, where the Supported BW subfield indicates a maximum BW that the first node supports in LPL mode communication with the second node. In some embodiments, the first LPL frame may further include a Supported MCS subfield, where the Supported BW subfield indicates a maximum MCS that the first node supports in LPL mode communication with the second node. In some embodiments, a Padding subfield of the first LPL frame may indicate an amount of padding to be included in an Active mode frame. In some embodiments, a Transition Duration subfield of the first LPL frame may indicate a duration associated with a transition of the first node from Active mode to LPL mode.

[0132] In some embodiments, the instructions stored in the memory, when executed by the at least one processor, can further cause the at least one processor to generate the first active frame, the first active frame indicating a transition from the LPL mode to an active mode, the first active frame including a padding amount indicated in a padding subfield of the first LPL frame. In some embodiments, the instructions stored in the memory, when executed by the at least one processor, can further cause the at least one processor to transmit the first active frame to the second node during an LPL mode period.

[0133] In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to receive a second active frame from the second node at a start of an active mode period. In some embodiments, the instructions stored in memory, when executed by the at least one processor, further cause the at least one processor to generate an active mode frame.

[0134] In some embodiments, the instructions stored in the memory, when executed by the at least one processor, may further cause the at least one processor to transmit the active mode frame to the second node during the active mode period.

[0135] In some embodiments, the first active frame may be an RTS frame, and in some embodiments, the second active frame may be a CTS frame.

[0136] The foregoing description of specific embodiments reveals the general nature of the present invention, such that those skilled in the art can readily modify and / or adapt such specific embodiments for various applications without departing from the general concept of the present invention and without undue experimentation, applying knowledge of the art. Such adaptations and modifications are therefore intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the terms and phrases used herein are for the purpose of description and not of limitation. Accordingly, the terms and phrases used herein should be interpreted in light of the teaching and guidance by those of ordinary skill in the art.

[0137]

[0023] The embodiments of the present invention have been described above with the aid of functional blocks illustrating implementation of specified functions and their relationships. The boundaries of these functional blocks have been arbitrarily defined herein for convenience of description. Alternative boundaries may be defined so long as the specified functions and their relationships are appropriately performed.

[0138] The Summary and Abstract sections describe one or more exemplary embodiments of the invention contemplated by the inventors, but are not intended to describe every embodiment, and therefore are not intended to limit the scope of the invention and the appended claims in any way.

[0139] Various functional blocks, modules, and steps are disclosed above. The specific arrangements provided are exemplary and not intended to be limiting. Thus, the functional blocks, modules, and steps may be rearranged or combined in ways different from the examples provided above. Similarly, some embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permissible. The breadth and scope of the present invention should not be limited by any of the above exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A wireless communication method for the first node, The first node generates a first LPL frame having a first low-power listening (LPL) subfield set to "enabled," The first node transmits the first LPL frame having the first LPL subfield set to "enabled" to the second node, The process includes transmitting the first LPL frame having the first LPL subfield set to "enable" to the second node, and then enabling the LPL mode by the first node, wherein the first node remains in an awakened state during the LPL mode. The aforementioned wireless communication method is The first node receives a second LPL frame from the second node that has a second LPL subfield set to "enabled," The first node further includes identifying that the second LPL subfield in the second LPL frame received from the second node is set to "enabled," After transmitting the first LPL frame having the first LPL subfield set to "enable" to the second node, the first node enables the LPL mode. Enable the LPL mode in response to the transmission of the first LPL frame having the first LPL subfield set to "enabled" to the second node, or A wireless communication method comprising enabling the LPL mode in response to identifying that the second LPL subfield in the second LPL frame received from the second node is set to "enable".

2. The aforementioned wireless communication method is The first node generates a third LPL frame having a third LPL subfield set to "disabled," The first node transmits the third LPL frame having the third LPL subfield set to "disabled" to the second node, The first node further includes transmitting the third LPL frame having the third LPL subfield set to "disabled" to the second node, and then disabling the LPL mode. The wireless communication method according to claim 1.

3. The aforementioned wireless communication method is The first node receives a fourth LPL frame having a fourth LPL subfield set to "disabled" from the second node, The first node further includes identifying that the fourth LPL subfield in the fourth LPL frame received from the second node is set to "disabled," After transmitting the third LPL frame having the third LPL subfield set to "disabled" to the second node, enabling the LPL mode by the first node is: In response to the transmission of the third LPL frame having the third LPL subfield set to "disabled" to the second node, the LPL mode is disabled, or The LPL mode is disabled in response to identifying that the fourth LPL subfield in the fourth LPL frame received from the second node is set to "disabled". The wireless communication method according to claim 2.

4. The first node generates the first LPL frame having the first LPL subfield set to "enabled," The support bandwidth (BW) subfield of the first LPL frame is set to indicate the maximum BW that the first node supports in LPL mode communication with the second node. The Support Modulation Coding Scheme (MCS) subfield of the first LPL frame is set to indicate the maximum MCS supported by the first node in LPL mode communication with the second node. The padding subfield of the first LPL frame is set to indicate the amount of padding included in the active mode frame, or The method includes at least one of the following: setting the transition duration subfield of the first LPL frame to indicate the duration associated with the transition from the active mode to the LPL mode of the first node; The wireless communication method according to claim 1.

5. The aforementioned wireless communication method is During the LPL mode cycle period, the first node receives a first active frame from the second node, the first active frame indicating a transition from the LPL mode to the active mode, and the first active frame includes a padding amount. The first node generates a second active frame associated with active-mode communication, At the start of the active mode cycle, the first node transmits the second active frame to the second node, The first node receives an active mode frame from the second node during the active mode period, further comprising: The wireless communication method according to claim 1.

6. The first active frame is a request to send (RTS) frame, The aforementioned second active frame is a transmittable (CTS) frame. The wireless communication method according to claim 5.

7. The active mode is a high-power mode. The wireless communication method according to claim 5.

8. The first node's wireless communication device, At least one processor, It includes a memory for storing instructions, A wireless communication device of a first node, wherein when the instruction is executed by the at least one processor, the at least one processor is caused to perform the method according to any one of claims 1 to 7.

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