PRIORITY CLAIM

[0001] This application claims the benefit of priority under 35 USC 119(e) to U.S. Provisional Patent Application Serial No. 62/383,767, filed September 6, 2016, and U.S. Provisional Patent Application Serial No.

62/400,154, filed September 27, 2016, which applications are incorporated herein by reference in their entireties. TECHNICAL FIELD

[0002] Embodiments pertain to wireless networks and wireless communications. Some embodiments relate to Institute of Electrical and

Electronic Engineers (IEEE) 802.11 family of standards. Some embodiments relate to high-efficiency (HE) wireless local -area networks (WLANs). Some embodiments relate to IEEE 802.11 ax. Some embodiments relate to computer readable media, methods, and apparatuses for transmission opportunity (TXOP) announcement for TXOP power save. Some embodiments relate to computer readable media, methods, and apparatuses for power save announce frame.

Some embodiments relate to computer readable media, methods, and

apparatuses for power save announcement frame for opportunistic power save (OPS).

BACKGROUND

[0003] Efficient use of the resources of a wireless local-area network (WLAN) is important to provide bandwidth and acceptable response times to the users of the WLAN. However, often there are many devices trying to share the same resources and the devices may interfere with one another. For example, in instances when an access point (AP) is associated with a large number of wireless stations (STAs), the AP may be serving only a limited number of those STAs at any given time, resulting in potential long periods between downlink transmissions to a particular station. In this case, the particular station may remain awake for a long time to await transmission from the AP, which decreases the energy efficiency of the communication system. Additionally, the wireless devices may be moving and the signal quality may be changing. Moreover, wireless devices may need to operate with both newer protocols and with legacy device protocols.

BRIEF DESCRIPTION OF THE DRAWINGS [0004] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:

[0005] FIG. 1 is a block diagram of a radio architecture in accordance with some aspects of the present disclosure; [0006] FIG. 2 illustrates a front-end module circuitry for use in the radio architecture of FIG. 1 in accordance with some aspects of the present disclosure;

[0007] FIG. 3 illustrates a radio IC circuitry for use in the radio architecture of FIG. 1 in accordance with some aspects of the present disclosure;

[0008] FIG. 4 illustrates a baseband processing circuitry for use in the radio architecture of FIG.l in accordance with some aspects of the present disclosure;

[0009] FIG. 5 illustrates a WLAN in accordance with some

embodiments;

[0010] FIG. 6 illustrates a physical layer convergence procedure (PLCP) protocol data unit (PPDU);

[0011] FIG. 7 illustrates a common info field which can be used in connection with TXOP announcement for TXOP power save in accordance with some embodiments; [0012] FIG. 8 illustrates a user info field which can be used in connection with TXOP announcement for TXOP power save in accordance with some embodiments;

[0013] FIG. 9 illustrates a power save announce control frame (PSACF) which can be used in connection with opportunistic power save (OPS) announcement in accordance with some embodiments;

[0014] FIG. 10 illustrates a timing diagram of a method for TXOP announcement for TXOP power save in accordance with some embodiments;

[0015] FIG 11 illustrates a method TXOP announcement for TXOP power save in accordance with some embodiments;

[0016] FIG. 12 illustrates a method for power save announcement using a power save announce control frame (PSACF) in accordance with some embodiments;

[0017] FIG. 13 illustrates an HEW communication device in accordance with some embodiments; and

[0018] FIG. 14 illustrates a block diagram of an example machine upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform.

DESCRIPTION

[0019] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0020] FIG. 1 is a block diagram of a radio architecture 100 in accordance with some aspects of the present disclosure. Radio architecture 100 may include radio front-end module (FEM) circuitry 104, radio IC circuitry 106 and baseband processing circuitry 108. Radio architecture 100 as shown includes both Wireless Local Area Network (WLAN) functionality and

Bluetooth (BT) functionality although aspects of the disclosure are not so limited. In this disclosure, "WLAN" and "Wi-Fi" are used interchangeably.

[0021] FEM circuitry 104 may include a WLAN or Wi-Fi FEM circuitry 104A and a Bluetooth (BT) FEM circuitry 104B. The WLAN FEM circuitry 104A may include a receive signal path comprising circuitry configured to operate on WLAN RF signals received from one or more antennas 101, to amplify the received signals and to provide the amplified versions of the received signals to the WLAN radio IC circuitry 106A for further processing. The BT FEM circuitry 104B may include a receive signal path which may include circuitry configured to operate on BT RF signals received from one or more antennas 101, to amplify the received signals and to provide the amplified versions of the received signals to the BT radio IC circuitry 106B for further processing. FEM circuitry 104A may also include a transmit signal path which may include circuitry configured to amplify WLAN signals provided by the radio IC circuitry 106A for wireless transmission by one or more of the antennas 101. In addition, FEM circuitry 104B may also include a transmit signal path which may include circuitry configured to amplify BT signals provided by the radio IC circuitry 106B for wireless transmission by the one or more antennas 101. In the example of FIG. 1, although FEM 104A and FEM 104B are shown as being distinct from one another, aspects of the present disclosure are not so limited, and include within their scope the use of an FEM (not shown) that includes a transmit path and/or a receive path for both WLAN and BT signals, or the use of one or more FEM circuitries where at least some of the FEM circuitries share transmit and/or receive signal paths for both WLAN and BT signals.

[0022] Radio IC circuitry 106 as shown may include WLAN radio IC circuitry 106A and BT radio IC circuitry 106B. The WLAN radio IC circuitry 106A may include a receive signal path which may include circuitry to down- convert WLAN RF signals received from the FEM circuitry 104A and provide baseband signals to WLAN baseband processing circuitry 108 A. BT radio IC circuitry 106B may in turn include a receive signal path which may include circuitry to down-convert BT RF signals received from the FEM circuitry 104B and provide baseband signals to BT baseband processing circuitry 108B.

WLAN radio IC circuitry 106A may also include a transmit signal path which may include circuitry to up-convert WLAN baseband signals provided by the WLAN baseband processing circuitry 108 A and provide WLAN RF output signals to the FEM circuitry 104A for subsequent wireless transmission by the one or more antennas 101. BT radio IC circuitry 106B may also include a transmit signal path which may include circuitry to up-convert BT baseband signals provided by the BT baseband processing circuitry 108B and provide BT RF output signals to the FEM circuitry 104B for subsequent wireless transmission by the one or more antennas 101. In the example of FIG. 1, although radio IC circuitries 106A and 106B are shown as being distinct from one another, aspects of the present disclosure are not so limited, and include within their scope the use of a radio IC circuitry (not shown) that includes a transmit signal path and/or a receive signal path for both WLAN and BT signals, or the use of one or more radio IC circuitries where at least some of the radio IC circuitries share transmit and/or receive signal paths for both WLAN and BT signals.

[0023] In an example, the radio IC circuitry 106 can include one or more divider-less fractional phase locked loops (PLLs) for generating fractional frequency signals, such as signals with frequencies that are a fraction of a frequency of a reference signal.

[0024] Baseband processing circuity 108 may include a WLAN baseband processing circuitry 108 A and a BT baseband processing circuitry 108B. The WLAN baseband processing circuitry 108 A may include a memory, such as, for example, a set of RAM arrays in a Fast Fourier Transform or Inverse Fast Fourier Transform block (not shown) of the WLAN baseband processing circuitry 108 A Each of the WLAN baseband circuitry 108 A and the BT baseband circuitry 108B may further include one or more processors and control logic to process the signals received from the corresponding WLAN or BT receive signal path of the radio IC circuitry 106, and to also generate

corresponding WLAN or BT baseband signals for the transmit signal path of the radio IC circuitry 106. Each of the baseband processing circuitries 108 A and 108B may further include physical layer (PHY) and medium access control layer (MAC) circuitry, and may further interface with application processor 110 for generation and processing of the baseband signals and for controlling operations of the radio IC circuitry 106.

[0025] Referring still to FIG. 1, according to the shown embodiment,

WLAN-BT coexistence circuitry 113 may include logic providing an interface between the WLAN baseband circuitry 108 A and the BT baseband circuitry 108B to enable use cases requiring WLAN and BT coexistence. In addition, a switch 103 may be provided between the WLAN FEM circuitry 104A and the BT FEM circuitry 104B to allow switching between the WLAN and BT radios according to application needs. In addition, although the antennas 101 are depicted as being respectively connected to the WLAN FEM circuitry 104A and the BT FEM circuitry 104B, aspects of the present disclosure include within their scope the sharing of one or more antennas as between the WLAN and BT FEMs, or the provision of more than one antenna connected to each of FEM 104A or 104B.

[0026] In some aspects of the present disclosure, the front-end module circuitry 104, the radio IC circuitry ⁷ 106, and baseband processing circuitry 108 may be provided on a single radio card, such as wireless radio card 102. In some other aspects of the present disclosure, the one or more antennas 101, the FEM circuitry 104 and the radio IC circuitry 106 may be provided on a single radio card. In some other aspects of the present disclosure, the radio IC circuitry 106 and the baseband processing circuitry 108 may be provided on a single chip or integrated circuit (IC), such as IC 112.

[0027] In some aspects of the present disclosure, the wireless radio card

102 may include a WLAN radio card and may be configured for Wi-Fi communications, although the scope of the aspects of the present disclosure is not limited in this respect. In some of these aspects of the present disclosure, the radio architecture 100 may be configured to receive and transmit orthogonal frequency division multiplexed (OFDM) or orthogonal frequency division multiple access (OFDMA) communication signals over a multicarrier communication channel. The OFDM or OFDMA signals may comprise a plurality of orthogonal subcarriers.

[0028] In some of these multicarrier aspects of the present disclosure, radio architecture 100 may be part of a Wi-Fi communication station (STA) such as a wireless access point (AP), a base station or a mobile device including a Wi- Fi device. In some of these aspects of the present disclosure, radio architecture 100 may be configured to transmit and receive signals in accordance with specific communication standards and/or protocols, such as any of the Institute of Electrical and Electronics Engineers (IEEE) standards including, IEEE 802.1 ln-2009, IEEE 802.11-2016, IEEE 802.1 ln-2009, IEEE 802.1 lac, and/or IEEE 802.1 lax standards and/or proposed specifications for WLANs, although the scope of aspects of the present disclosure is not limited in this respect. Radio architecture 100 may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. [0029] In some aspects of the present disclosure, the radio architecture

100 may be configured for high-efficiency (HE) Wi-Fi (HEW) communications in accordance with the IEEE 802.1 lax standard. In these aspects of the present disclosure, the radio architecture 100 may be configured to communicate in accordance with an OFDMA technique, although the scope of the aspects of the present disclosure is not limited in this respect.

[0030] In some other aspects of the present disclosure, the radio architecture 100 may be configured to transmit and receive signals transmitted using one or more other modulation techniques such as spread spectrum modulation (e.g., direct sequence code division multiple access (DS-CDMA) and/or frequency hopping code division multiple access (FH-CDMA)), time- divisionmultiplexing (TDM) modulation, and/or frequency-division

multiplexing (FDM) modulation, although the scope of the aspects of the present disclosure is not limited in this respect.

[0031] In some aspects of the present disclosure, as further shown in FIG. 1, the BT baseband circuitry 108B may be compliant with a Bluetooth (BT) connectivity standard such as Bluetooth, Bluetooth 4.0 or Bluetooth 5.0, or any other iteration of the Bluetooth Standard. In aspects of the present disclosure that include BT functionality as shown for example in Fig. 1, the radio architecture 100 may be configured to establish a BT synchronous connection ori ented (SCO) link and/or a BT low energy (BT LE) link. In some of the aspects of the present disclosure that include functionality, the radio architecture 100 may be configured to establish an extended SCO (eSCO) link for BT communications, although the scope of the aspects of the present disclosure is not limited in this respect. In some of these aspects of the present disclosure that include a BT functionality, the radio architecture may be configured to engage in a BT Asynchronous Connection-Less (ACL) communications, although the scope of the aspects of the present disclosure is not limited in this respect. In some aspects of the present disclosure, as shown in FIG. 1, the functions of a BT radio card and WLAN radio card may be combined on a single wireless radio card, such as single wireless radio card 102, although aspects of the present disclosure are not so limited, and include within their scope discrete WLAN and BT radio cards

[0032] In some aspects of the present disclosure, the radio-architecture

100 may include other radio cards, such as a cellular radio card configured for cellular (e.g., 3GPP such as LTE, LTE-Advanced or 5G communications). [0033] In some IEEE 802.11 aspects of the present disclosure, the radio architecture 100 may be configured for communication over various channel bandwidths including bandwidths having center frequencies of about 900 MHz, 2.4 GHz, 5 GHz, and bandwidths of about 1 MHz, 2 MHz, 2.5 MHz, 4 MHz, 5MHz, 8 MHz, 10 MHz, 16 MHz, 20 MHz, 40MHz, 80MHz (with contiguous bandwidths) or 80+80MHz (160MHz) (with non-contiguous bandwidths). In some aspects of the present disclosure, a 320 MHz channel bandwidth may be used. The scope of the aspects of the present disclosure is not limited with respect to the above center frequencies however.

[0034] FIG. 2 illustrates FEM circuitry 200 in accordance with some aspects of the present disclosure. The FEM circuitry 200 is one example of circuitry that may be suitable for use as the WLAN and/or BT FEM circuitry 104A/104B (FIG. 1), although other circuitry configurations may also be suitable.

[0035] In some aspects of the present disclosure, the FEM circuitry 200 may include a TX/RX switch 202 to switch between transmit mode and receive mode operation. The FEM circuitry 200 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry 200 may include a low-noise amplifier (LNA) 206 to amplify received RF signals 203 and provide the amplified received RF signals 207 as an output (e.g., to the radio IC circuitry 106 (FIG. 1)). The transmit signal path of the circuitry 200 may include a power amplifier (PA) 210 to amplify input RF signals 209 (e.g., provided by the radio IC circuitry 106), and one or more filters 212, such as band-pass filters (BPFs), low-pass filters (LPFs) or other types of filters, to generate RF signals 215 for subsequent transmission (e.g., by one or more of the antennas 101 (FIG. 1))·

[0036] In some dual-mode aspects of the present disclosure for Wi-Fi communication, the FEM circuitry 200 may be configured to operate in either the 2.4 GHz frequency spectrum or the 5 GHz frequency spectrum. In these aspects of the present disclosure, the receive signal path of the FEM circuitry 200 may include a receive signal path duplexer 204 to separate the signals from each spectrum as well as provide a separate LNA 206 for each spectrum as shown. In these aspects of the present disclosure, the transmit signal path of the FEM circuitry 200 may also include a power amplifier 210 and a filter 212, such as a BPF, a LPF or another type of filter for each frequency spectrum and a transmit signal path duplexer 214 to provide the signals of one of the different spectrums onto a single transmit path for subsequent transmission by the one or more of the antennas 101 (FIG. 1). In some aspects of the present disclosure, BT communications may utilize the 2.4 GHZ signal paths and may utilize the same FEM circuitry 200 as the one used for WLAN communications.

[0037] FIG. 3 illustrates radio IC circuitry 300 in accordance with some aspects of the present disclosure. The radio IC circuitry 300 is one example of circuitry that may be suitable for use as the WLAN or BT radio IC circuitry 106A/106B (FIG. 1), although other circuitry configurations may also be suitable.

[0038] In some aspects of the present disclosure, the radio IC circuitry

300 may include a receive signal path and a transmit signal path. The receive signal path of the radio IC circuitry 300 may include at leastmixer circuitry 302, such as, for example, down-conversion mixer circuitry, amplifier circuitry 306 and filter circuitry 308. The transmit signal path of the radio IC circuitry 300 may include at least filter circuitry 312 and mixer circuitry 314, such as, for example, up-conversion mixer circuitry. Radio IC circuitry 300 may also include synthesizer circuitry 304 for synthesizing a frequency 305 for use by the mixer circuitry 302 and the mixer circuitry 314. The mixer circuitry 302 and/or 314 may each, according to some aspects of the present disclosure, be configured to provide direct conversion functionality. The latter type of circuitry presents a much simpler architecture as compared with standard super-heterodyne mixer circuitries, and any flicker noise brought about by the same may be alleviated for example through the use of OFDM modulation. Fig. 3 illustrates only a simplified version of a radio IC circuitry, and may include, although not shown, aspects of the present disclosure where each of the depicted circuitries may include more than one component. For instance, mixer circuitry 302 and/or 314 may each include one or more mixers, and filter circuitries 308 and/or 312 may each include one or more filters, such as one or more BPFs and/or LPFs according to application needs. For example, when mixer circuitries are of the direct-conversion type, they may each include two or more mixers.

[0039] In some aspects of the present disclosure, mixer circuitry 302 may be configured to down-convert RF signals 207 received from the FEM circuitry 104 (FIG. 1) based on the synthesized frequency 305 provided by synthesizer circuitry 304. The amplifier circuitry 306 may be configured to amplify the down-converted signals and the filter circuitry 308 may include a LPF configured to remove unwanted signals from the down-converted signals to generate output baseband signals 307. Output baseband signals 307 may be provided to the baseband processing circuitry 108 (FIG. 1) for further processing. In some aspects of the present disclosure, the output baseband signals 307 may be zero-frequency baseband signals, although this is not a requirement. In some aspects of the present disclosure, mixer circuitry 302 may comprise passive mixers, although the scope of the aspects of the present disclosure is not limited in this respect. [0040] In some aspects of the present disclosure, the mixer circuitry 314 may be configured to up-convert input baseband signals 311 based on the synthesized frequency 305 provided by the synthesizer circuitry 304 to generate RF output signals 209 for the FEM circuitry 104. The baseband signals 311 may be provided by the baseband processing circuitry 108 and may be filtered by filter circuitry 312. The filter circuitry 312 may include a LPF or a BPF, although the scope of the aspects of the present disclosure is not limited in this respect.

[0041] In some aspects of the present disclosure, the mixer circuitry 302 and the mixer circuitry 314 may each include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion respectively with the help of synthesizer 304. In some aspects of the present disclosure, the mixer circuitry 302 and the mixer circuitry 314 may each include two or more mixers each configured for image rejection (e.g., Hartley image rejection). In some aspects of the present disclosure, the mixer circuitry 302 and the mixer circuitry 314 may be arranged for direct down-conversion and/or direct up- conversion, respectively. In some aspects of the present disclosure, the mixer circuitry 302 and the mixer circuitry 314 may be configured for superheterodyne operation, although this is not a requirement.

[0042] Mixer circuitry 302 may comprise, according to one embodiment: quadrature passive mixers (e.g., for the in-phase (I) and quadrature phase (Q) paths). In such an embodiment, RF input signal 207 from Fig. 3 may be down- converted to provide I and Q baseband output signals to be sent to the baseband processor

[0043] Quadrature passive mixers may be driven by zero and ninety- degree time-varying LO switching signals provided by a quadrature circuitry which may be configured to receive a LO frequency (fLO) from a local oscillator or a synthesizer, such as LO frequency 305 of synthesizer 304 (FIG. 3). In some aspects of the present disclosure, the LO frequency may be the carrier frequency, while in other aspects of the present disclosure, the LO frequency may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency), generated by, e.g., fractional PLL circuitry. In some aspects of the present disclosure, the zero and ninety-degree time-varying switching signals may be generated by the synthesizer, although the scope of the aspects of the present disclosure is not limited in this respect.

[0044] In some aspects of the present disclosure, the LO signals may differ in duty cycle (the percentage of one period in which the LO signal is high) and/or offset (the difference between start points of the period). In some aspects of the present disclosure, the LO signals may have a 25% duty cycle and a 50% offset. In some aspects of the present disclosure, each branch of the mixer circuitry (e.g., the in-phase (I) and quadrature phase (Q) path) may operate at a 25% duty cycle, which may result in a significant reduction is power consumption.

[0045] The RF input signal 207 (FIG. 2) may comprise a balanced signal, although the scope of the aspects of the present disclosure is not limited in this respect. The I and Q baseband output signals may be provided to low- nose amplifier, such as amplifier circuitry 306 (FIG. 3) or to filter circuitry 308 (FIG. 3).

[0046] In some aspects of the present disclosure, the output baseband signals 307 and the input baseband signals 311 may be analog baseband signals, although the scope of the aspects of the present disclosure is not limited in this respect. In some alternate aspects of the present disclosure, the output baseband signals 307 and the input baseband signals 311 may be digital baseband signals. In these alternate aspects of the present disclosure, the radio IC circuitry may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry. [0047] In some dual-mode aspects of the present disclosure, a separate radio IC circuitry may be provided for processing signals for each spectrum, or for other spectrums not mentioned here, although the scope of the aspects of the present disclosure is not limited in this respect.

[0048] In some aspects of the present disclosure, the synthesizer circuitry

304 may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the aspects of the present disclosure is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 304 may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. According to some aspects of the present disclosure, the synthesizer circuitry 304 may include digital synthesizer circuitry. An advantage of using a digital synthesizer circuitry is that, although it may still include some analog components, its footprint may be scaled down much more than the footprint of an analog synthesizer circuitry. In some aspects of the present disclosure, frequency input into synthesizer circuity 304 may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. A divider control input may further be provided by either the baseband processing circuitry 108 (FIG. 1) or the application processor 110 (FIG. 1) depending on the desired output frequency 305. In some aspects of the present disclosure, a divider control input (e.g., N) may be determined from a look-up table (e.g., within a Wi-Fi card) based on a channel number and a channel center frequency as determined or indicated by the application processor 110.

[0049] In some aspects of the present disclosure, synthesizer circuitry

304 may be configured to generate a carrier frequency as the output frequency 305, while in other aspects of the present disclosure, the output frequency 305 may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some aspects of the present disclosure, the output frequency 305 may be a LO frequency (fLO).

[0050] FIG. 4 illustrates a functional block diagram of baseband processing circuitry 400 in accordance with some aspects of the present disclosure. The baseband processing circuitry 400 is one example of circuitry that may be suitable for use as the baseband processing circuitry 108 (FIG. 1), although other circuitry configurations may also be suitable. The baseband processing circuitry 400 may include a receive baseband processor (RX BBP) 402 for processing receive baseband signals 309 provided by the radio IC circuitry 106 (FIG. 1) and a transmit baseband processor (TX BBP) 404 for generating transmit baseband signals 311 for the radio IC circuitry 106. The baseband processing circuitry 400 may also include control logic 406 for coordinating the operations of the baseband processing circuitry 400.

[0051] In some aspects of the present disclosure (e.g., when analog baseband signals are exchanged between the baseband processing circuitry 400 and the radio IC circuitry 106), the baseband processing circuitry 400 may include ADC 410 to convert analog baseband signals received from the radio IC circuitry 106 to digital baseband signals for processing by the RX BBP 402. In these aspects of the present disclosure, the baseband processing circuitry 400 may also include DAC 412 to convert digital baseband signals from the TX BBP 404 to analog baseband signals. [0052] In some aspects of the present disclosure that communicate

OFDM signals or OFDMA signals, such as through baseband processor 108 A, the transmit baseband processor 404 may be configured to generate OFDM or OFDMA signals as appropriate for transmission by performing an inverse fast Fourier transform (IFFT). The receive baseband processor 402 may be configured to process received OFDM signals or OFDMA signals by performing an FFT. In some aspects of the present disclosure, the receive baseband processor 402 may be configured to detect the presence of an OFDM signal or OFDMA signal by performing an autocorrelation, to detect a preamble, such as a short preamble, and by performing a cross-correlation, to detect a long preamble. The preambles may be part of a predetermined frame structure for Wi-Fi communication.

[0053] Referring back to FIG. 1, in some aspects of the present disclosure, the antennas 101 (FIG. 1) may each comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, mi crostrip antennas or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) aspects of the present disclosure, the antennas may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result. Antennas 101 may each include a set of phased-array antennas, although aspects of the present disclosure are not so limited. [0054] Although the radio-architecture 100 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some aspects of the present disclosure, the functional elements may refer to one or more processes operating on one or more processing elements.

[0055] FIG. 5 illustrates a WLAN 500 in accordance with some embodiments. The WLAN 500 may comprise a basic service set (BSS) 500 that may include an HE access point (AP) 502, which may be an AP, a plurality of high-efficiency wireless (e.g., IEEE 802.11 ax) (HE) stations 504, and a plurality of legacy (e.g., IEEE 802.1 ln/ac) devices 506.

[0056] The HE access point 502 may be an AP using the IEEE 802.11 protocol to transmit and receive. The HE access point 502 may be a base station. The HE access point 502 may use other communications protocols as well as the IEEE 802.11 protocol. The IEEE 802.11 protocol may be IEEE 802.11 ax. The IEEE 802.11 protocol may include using orthogonal frequency division multiple-access (OFDMA), time di vi sion multiple access (TDMA), and/or code division multiple access (CDMA). The IEEE 802.11 protocol may include a multiple access technique. For example, the IEEE 802.11 protocol may include space-division multiple access (SDMA) and/or multiple-user multiple-input multiple-output (MU-MIMO). There may be more than one HE access point 502 that i s part of an extended service set (ESS). A controller (not illustrated) may store information that is common to the more than one HE access points 502.

[0057] The legacy devices 506 may operate in accordance with one or more of IEEE 802.11 a/b/g/n/ac/ad/af/ah/aj/ay, or another legacy wireless communication standard. The legacy devices 506 may be STAs or IEEE STAs. The HE STAs 504 (e.g., 504.1, 504.2, 504.3, and 504.4) may be wireless transmit and receive devices such as cellular telephone, portable electronic wireless communication devices, smart telephone, handheld wireless device, wireless glasses, wireless watch, wireless personal device, tablet, or another device that may be transmitting and receiving using the IEEE 802.11 protocol such as IEEE 802.1 lax or another wireless protocol. In some embodiments, the HE STAs 504 may be termed high efficiency (HE) stations.

[0058] The HE access point 502 may communicate with legacy devices

506 in accordance with legacy IEEE 802.11 communication techniques. In example embodiments, the HE access point 502 may also be configured to communicate with HE STAs 504 in accordance with legacy IEEE 802.11 communication techniques.

[0059] In some embodiments, an HE frame may be configurable to have the same bandwidth as a channel. The HE frame may be a PPDU. In some embodiments, there may be different types of PPDUs that may have different fields and different physical layers and/or different media access control (MAC) layers.

[0060] The bandwidth of a channel may be 20MHz, 40MHz, 80MHz,

160MHz, 320MHz contiguous bandwidths, or an 80+80MHz (160MHz) non- contiguous bandwidth. In some embodiments, the bandwidth of a channel may be 1 MHz, 1.25 MHz, 2.03 MHz, 2.5 MHz, 4.06 MHz, 5 MHz and 10 MHz, or a combination thereof or another bandwidth that is less or equal to the available bandwidth may also be used. In some embodiments the bandwidth of the channels may be based on a number of active data subcarriers. In some embodiments the bandwidth of the channels is based on 26, 52, 506, 242, 484, 996, or 2x996 active data subcarriers or tones that are spaced by 20 MHz. In some embodiments the bandwidth of the channels is 256 tones spaced by 20 MHz. In some embodiments the channels are multiple of 26 tones or a multiple of 20 MHz. In some embodiments a 20 MHz channel may comprise 242 active data subcarriers or tones, which may determine the size of a Fast Fourier Transform (FFT). An allocation of a bandwidth or a number of tones or sub- carriers may be termed a resource unit (RU) allocation in accordance with some embodiments.

[0061] In some embodiments, the 26-subcarrierRU and 52-subcarrier

RU are used in the 20 MHz, 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA HE PPDU formats. In some embodiments, the 106-subcarrier RU is used in the 20 MHz, 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-ΜΓΜΟ HE PPDU formats. In some embodiments, the 242-subcarrierRU is used in the 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU- MIMO HE PPDU formats. In some embodiments, the 484-subcarrier RU is used in the 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-MEVIO HE PPDU formats. In some embodiments, the 996-subcarrier RU is used in the 160 MHz and 80+80 MHz OFDMA and MU-ΜΓΜΟ HE PPDU formats.

[0062] An HE frame may be configured for transmitting a number of spatial streams, which may be in accordance with MU-MIMO and may be in accordance with OFDMA. In other embodiments, the HE access point 502, HE STA 504, and/or legacy device 506 may also implement different technologies such as code division multiple access (CDMA) 2000, CDMA 2000 IX, CDMA 2000 Evolution-Data Optimized (EV-DO), Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Long Term

Evolution (LTE), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)),

BlueTooth®, or other technologies.

[0063] Some embodiments relate to HE communications. In accordance with some IEEE 802.1 1 embodiments, e.g., IEEE 802.1 lax embodiments, an HE access point 502 may operate as an HE access point which may be arranged to contend for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium for an HE control period. In some

embodiments, the HE control period may be termed a transmission opportunity (TXOP). The HE access point 502 may transmit an HE master-sync

transmission, which may be a trigger frame or HE control and schedule transmission, at the beginning of the HE control period. The HE access point 502 may transmit a time duration of the TXOP and sub-channel information. During the HE control period, HE ST As 504 may communicate with the HE access point 502 in accordance with a non-contention based multiple access technique such as OFDMA or MU-MIMO. This is unlike conventional WLAN communications in which devices communicate in accordance with a contention-based communication technique, rather than a multiple access technique. During the HE control period, the HE access point 502 may communicate with HE stations 504 using one or more HE frames. During the HE control period, the HE STAs 504 may operate on a sub-channel smaller than the operating range of the HE access point 502. During the HE control period, legacy stations refrain from communicating. The legacy stations 506 may need to receive the communication from the HE access point 502 to defer from communicating.

[0064] In accordance with some embodiments, during the TXOP, the HE STAs 504 may contend for the wireless medium with the legacy devices 506 being excluded from contending for the wireless medium during the master-sync transmission. In some embodiments the trigger frame may indicate an UL-MU- MIMO and/or UL OFDMA TXOP. In some embodiments, the trigger frame may include a DL-MU-MIMO and/or DL-OFDMA with a schedule indicated in a preamble portion of trigger frame.

[0065] In some embodiments, the multiple-access technique used during the HE TXOP may be a scheduled OFDMA technique, although this is not a requirement. In some embodiments, the multiple access technique may be a time-division multiple access (TDMA) technique or a frequency division multiple access (FDMA) technique. In some embodiments, the multiple access technique may be a space-divisionmultiple access (SDMA) technique. In some embodiments, the multiple access technique may be a Code division multiple access (CDMA).

[0066] The HE access point 502 may also communicate with legacy stations 506 and/or HE stations 504 in accordance with legacy IEEE 802.1 1 communication techniques. In some embodiments, the HE access point 502 may also be configurable to communicate with HE stations 504 outside the HE TXOP in accordance with legacy IEEE 802.1 1 communication techniques, although this is not a requirement.

[0067] In some embodiments the HE station 504 may be a "group owner" (GO) for peer-to-peer modes of operation. A wireless device may be an HE station 504 or an HE access point 502.

[0068] In some embodiments, the HE station 504 and/or the HE access point 502 may be configured to operate in accordance with IEEE 802.11-2016. An HE station 504 and/or an HE access point 502 may be termed an HE device (e.g., station or AP), if the HE device complies with the wireless communication standard IEEE 802.1 lax.

[0069] In some embodiments, the HE stations 504 may have limited power. In some embodiments, the HE stations 504 may have limited power and may transmit on an RU less than 20 MHz in order to reach the HE access point 502.

[0070] In some embodiments associated with IEEE 802.1 lax

communication systems, a spatial reuse (SR) field may be used in HE PPDUs to enable spatial reuse. There may be four HE PPDU formats: HE single user (SU) PPDU, HE extended range (ER) SU PPDU, HE multi-user (MU) PPDU, and HE trigger-based (TB) PPDU (HE TB PPDU). In some embodiments, 4 bits of spatial reuse field may be allocated for HE SU PPDU, HE ER SU PPDU, and HE MU PPDU. In some embodiments, 16 bits of spatial reuse field are allocated for an HE TB PPDU, where the 16 bits may be divided into 4 separate spatial reuse subfields with 4 bits for each spatial reuse subfield. [0071] In an example, to enable wireless stations (STAs) to activate power save mode for the duration of a TXOP, the AP can send (e.g., at the beginning of the TXOP), a TXOP announcement frame (e.g., a multiple user request-to-send, or MU-RTS, frame), which identifies all the STAs that will be addressed or triggered during the TXOP. In an example, the announcement frame can indicate which STAs will be triggered or addressed during the TXOP and, which STAs will not be triggered or addressed during the current TXOP. In an example, the announcement frame can indicate a scheduling time target (e.g., a specific time within the current TXOP or a subsequent TXOP) for one or more of the STAs, which indicates a time that the STA will be triggered or addressed.

[0072] In an example, the announcement frame can indicate, which of the STAs are required to send feedback (such as a clear-to-send (CTS) response frame in response to the MU-RTS frame) and which STAs that are addressed do not need to send back such feedback (e.g., a CTS frame).

[0073] In an example, STAs that will not be addressed or triggered in the current TXOP can activate low -power mode or sleep mode for the duration of the TXOP, which can allow for significant power savings.

[0074] In an example, additional information may be included in the

TXOP announcement (e.g., MU-RTS) frame for intra-TXOP scheduling (e.g., by using one or more bits within the MU-RTS trigger frame, as indicated herein below). For example, STAs that are addressed in the TXOP, but X time after the MU-RTS is sent, the timing information X can be communicated in, e.g., a per- STA info field of the MU-RTS where the STA address or identification is (i.e., a user info field associated with the specific STA).

[0075] In an example, the MU-RTS frame can include information for

STAs that are not scheduled within the current TXOP. For example, the MU- RTS can include a TXOP identifier indicating a subsequent TXOP during which the STA will be addressed or triggered. The TXOP identifier can include a specific time in the future (after the current TXOP), when the AP is planning on scheduling the STA.

[0076] In an example, a power- save announce control frame (PSACF) can be periodically sent/broadcasted by the AP in a regular manner. For example, the PSACF can be communicated with beacons (e.g., every 100 milliseconds, or 100 ms) or with mini -beacons (every 20-50 ms), or with fast initial link setup (FILS) discovery frames (every 20 ms). The duration between two PSACF can be static. The duration between two sequential PSACFs can be set as the service period, which can be included as information within the PSACF that directly precedes the current service period.

[0077] In an example, the PSACF can include information about the next service period (starting from reception of the current PSACF until reception of the next PSACF). In an example, the PSACF can include a list of STAs that will surely be scheduled during the service period, and a list of STAs that will surely not be scheduled during the service period (unless some event arises, such as a specific request from that STA during the service period).

[0078] In an example, the list of ST As can be included in the form of a bitmap (e.g., TIM-like bitmap) with the association identifiers ( AIDs) of the STAs. More specifically, each index of the bitmap can correspond to an AID (and therefore an STA). For example, the bit can be set to 1 to indicate that the STA will surely not be scheduled, and to 0 if it surely will be scheduled.

[0079] In an example, the bitmaps can provide additional information by associating more than 1 bit per AID in the bitmap (e.g., bits 11 indicate STA will be surely scheduled, bits 00 indicate STA will surely not be scheduled, and bits 10 or 01 indicate undetermined status).

[0080] In an example, to lower the size of the bitmaps, SFA-IDs (short

PHY-feedback allocation identification) can be used instead of the AIDs.

[0081] In an example, the PSACF can include additional information, such as identification of a specific trigger frame and a time in the future when the trigger frame will be communicated. Example specific trigger frames include a trigger frame that solicits an OFDMA random access frame, a trigger frame that solicits a short PHY-feedback, and so forth.

[0082] In an example, an STA receiving the PSACF can activate a power save or sleep mode if the STA will not be scheduled during the current service period associated with the received PSACF. In instances when the STA will be scheduled in the current service period, the STA can remain awake and not activate power save mode.

[0083] FIG. 6 illustrates a physical layer convergence procedure (PLCP) protocol data unit (PPDU) 600. The PPDU 600 may include a preamble 602 portion and a media access control (MAC) 604 portion. The preamble 602 portion may include a legacy portion 606 and an HE portion 608. The legacy portion 606 may include a legacy length 610 field. A frame (PPDU) duration may be part of the legacy portion 606, HE portion 608, and/or MAC 604 portion. The HE portion 608 may include one or more of an HE preamble length 612 field, an HE signal (SIG) A 614 field, and/or an HE SIG B 616 field.

[0084] The preamble 602 portion and MAC 604 portion may be transmitted on different RUs or bandwidths. In an example, the MAC 604 portion may include (e.g., when the PPDU 600 is a trigger frame, such as an MU-RTS frame) one or more of a frame control (FC) 618 field, a common info field 620, and user info fields 622, ..., 624. The legacy length 610 field may be an indication of the length of the PPDU 600 in a SIG field of the legacy portion 606, e.g., a number of symbols. The HE preamble length 612 may be an indication of the length of the PPDU 600 in an HE SIG field, e.g., HE SIG A 614 field. [0085] The FC 618 may include information related to the PPDU 600.

For example, the FC 618 may include a field that indicates the type of PPDU the PPDU 600 is, e.g., HE MU PPDU TF.

[0086] The PPDU 600 can further include a common info field 620 and user info fields 622 - 624. A more detai led diagram of the common info fi eld 620 is illustrated in FIG. 7. A more detailed diagram of the user info field 622 is illustrated in FIG. 8.

[0087] FIG. 7 illustrates a common info field which can be used in connection with TXOP announcement for TXOP power save in accordance with some embodiments. Referring to FIG. 7, the common info field 620 can include the following subfields: trigger type 702 (indicating a type of trigger frame); length 704 (indicating the value of the L-SIG length field of the HE trigger- based PPDU that is the response to the trigger frame); GI and LTF type 706 (indicating the guard interval (GI) and HE long training field (HE-LTF)) type pf the HE TB PPDU response); MU-MEVIO LTF mode 708 (the LTF mode of the UL MU-MIMO HE TB PPDU); number of HE-LTF 710; STBC 712 (status of STBC encoding of HE TB PPDU response); LDPC extra symbol 714 (status of LDPC extra symbol segment); AP TX power 716 (combined average power per 20 MHz bandwidth of all transmit antennas used by the AP); packet extension 718 (packet extension duration of the HE TB PPDU); spatial reuse 720 (has the value of the spatial reuse field in the HE-SIG-A field of the HE TB PPDU transmitted as a response to the trigger frame); HE-SIG-A reserved subfield 722; and reserved subfield 724.

[0088] FIG. 8 illustrates a user info field which can be used in connection with TXOP announcement for TXOP power save in accordance with some embodiments. Referring to FIG. 8, the user info field 622 can include the Association ID (AID) 802 of the STA associated with the user info field 622; an RU allocation subfield 804 (the RU used by the HE TB PPDU of the STA identified by the AID in 802); coding type 806 (the code type of the HE TB PPDU response of the STA i dentified in 802), dual carrier modul ation (DCM) subfield 808 (dual carrier modulation of the HE TB PPDU response); spatial streams (SS) allocation 810 (the spatial streams of the HE TB PPDU response); target RSSI 812 (target received signal power of the HE TB PPDU response); and a reserved subfield 814.

[0089] In an example, one or more of the subfields of the common info field 620 and/or a per user info field (e.g., one or more of 622-624) can be used to provide additional information for TXOP announcement for TXOP power save. More specifically, the subfields of the common info field and/or a per user info field can include AIDs 626, ..., 628 (e.g., each STA AID can use a corresponding per user info field 622, ..., 624); clear-to-send (CTS) feedback required (CTSFR) information 630, 632 (can include an indication per STA on whether or not the STA is required to send back a response acknowledgement frame, such as a CTS frame, in response to the MU-RTS trigger frame);

scheduling time target (STT) information 634, ..., 636 (can be included per STA and can indicate a specific lime when the AP will be sending information for the STA so that the STA can be awake at the designated time); and TXOP identifier (ΤΧΟΡΓ) information 638, ..., 640 (can be included per STA and can indicate a specific time in the future when a different TXOP will take place during which the STA will be addressed or triggered).

[0090] In an example, a per user info field (e.g., 622, ..., 624) can be included for all the STAs that will be scheduled in a TXOP. For each STA, a per user info field (e.g., one of 622, ..., 624) can include the AID of the STA and an indication whether CTS response is needed or not (e.g., CTSFR information 630, ..., 632 can be included). For example, one or more of the RU allocation bits 804 can be used for the CTSFR information. Alternatively, other subfields can be used instead (such as coding type subfield 806) in order to indicate if a CTS response is needed or not.

[0091] In an example, the AP can define a group ID for a group of STAs, with the group ID being indicated in the AID field of a per user info field. All STAs associated with the group ID can use the TXOP related information in the per user info field associated with the group ID, and determine whether to activate low power or sleep mode based on whether or not the STA will be addressed or triggered in the current TXOP. [0092] In an example, additional information can be included in the

TXOP announcement (e.g., MU-RTS) frame for intra-TXOP scheduling. For example, STAs that are addressed in the TXOP, but X time after the MU-RTS is sent, can find the X timing information in the per-STA info field of the MU-RTS where their address is. For instance, the scheduling time target can be included in the per-user info field of a STA by reusing the SS allocation 810 or target RSSI 812 subfields. As used herein, the term "X time" or "X timing

information" indicates variable amount of time (and in an example, such time can be pre-set or pre-determined).

[0093] In an example, additional information can be included in the TXOP announcement (e.g., MU-RTS) frame for scheduling STAs outside of the TXOP. For example, STAs that are not scheduled in the current TXOP can also be included in the MU-RTS frame, with an indication that they are not scheduled in the current TXOP, but with an indication of the time in the future (e.g., during a subsequent TXOP) where the AP is planning on scheduling this STA. The indication (e.g., STT 634, 636) of whether the STAs are addressed in the present TXOP or not can be done by reusing, e.g., the DCM bit 808 in the peruser info field. The scheduling time target (STTs 634, ..., 636) can be also included by reusing the SS allocation 810 or target RSSI 812 subfields.

[0094] FIG. 9 illustrates a power save announce control frame (PSACF) which can be used in connection with opportunistic power save (OPS) announcement in accordance with some embodiments. In an example, a power- save announce control frame (PSACF) 900 can be periodically sent/broadcasted by the AP in a regular manner for opportunistic power save (OPS)

functionalities. For example, the PSACF 900 can be communicated with beacons (e.g., every 100 milliseconds, or 100 ms) or with mini -beacons (every 20-50 ms), TIM frames, or with FILS discovery frames (every 20 ms). The duration between two PSACF can be static. The duration between two sequential PSACFs can be set as the service period (SP), which can be included as information within the PSACF that directly precedes the current service period.

[0095] In an example, an HE AP (e.g., 502) can be set as an OPS AP by setting an OPS Capable subfield (e.g., to 1) in an HE Capabilities element. In an example, an HE STA (e.g., 504) can be set as an OPS STA by setting an OPS Capable subfield (e.g., to 0) in an HE Capabilities element.

[0096] In an example, the PSACF can include information 902 about the next service period (starting from reception of the current PSACF until reception of the next PSACF). In an example, the PSACF can include a list (906) of STAs that will surely be scheduled during the service period, and a list (904) of STAs that will surely not be scheduled during the service period (unless some event arises, such as a specific request from that STA during the service period). In this regard, opportunistic power save functionality can be allowed for OPS STAs that are not scheduled within the current service period. [0097] In an example, an OPS AP can split a beacon interval into several periodic broadcast target weight time (TWT) SPs, and provide scheduling information for all STAs at the beginning of each SP (e.g., by using the bitmap information 904 and 906). [0098] In an example, the list of STAs can be included in the form of a bitmap (e.g., ΊΊΜ-like bitmap) with the association identifiers (AIDs) of the STAs. More specifically, each index of the bitmap can correspond to an AID (and therefore an STA). For example, the bit can be set to 1 to indicate that the STA will surely not be scheduled, and to 0 if it surely will be scheduled. [0099] In an example, the bitmaps can provide additional information by associating more than 1 bit per AID in the bitmap (e.g., bits 11 indicate STA will be surely scheduled, bits 00 indicate STA will surely not be scheduled, and bits 10 or 01 indicate undetermined status).

[00100] In an example, to lowerthe size of the bitmaps, SFA-IDs (short PHY-feedback allocation identification) can be used instead of the AIDs.

[00101] In an example, the PSACF can include additional information, such as identification 908, ... , 910 of specific trigger frames and times in the future when the trigger frames will be communicated. Example specific trigger frames include OFDMA random access frames, trigger frame for short PHY- feedback for resource request, and so forth.

[00102] In an example, an STA receiving the PSACF can activate a power save or sleep mode if the STA will not be scheduled during the current service period associated with the received PSACF. In instances when the STA will be scheduled in the current service period, the STA can remain awake and not activate power save mode.

[00103] FIG. 10 illustrates a timing diagram of a method 1000 for TXOP announcement for TXOP power save in accordance with some embodiments. Illustrated in FIG. 10 is time 1002 along a horizontal axis, transmitter/receiver 1004 along a vertical axis, frequency 1069 along a vertical axis, and operations 1006 along the top. HE stations 504.1, 504.2, and 504.3 are associated with HE access point (AP) 502 in BSS 500. The HE STA 504.1 can have an association ID (AID) indicated in FIG. 10 as AID1. Similarly, HE STAs 504.2 and 504.3 can have AIDs indicated in FIG. 10 as AID5 and AID6, respectively.

[00104] The frequency 1069 may be a bandwidth (e.g., an RU). The frequencies 1069 may overlap. For example, frequency 1070 may be the same or overlap with frequencies 1072, 1074, and/or 1076.

[00105] The method 1000 begins with operation 1008 with FIE access point 502 contending for the wireless medium, e.g., performing a clear channel assessment (CCA). The method 1000 continues at operation 1010 with the HE access point 502 transmitting an MU-RTS frame 1020. The MU-RTS frame 1020 can designate a TXOP 1016. The MU-RTS frame 1020 can also include additional information to trigger power saving functionalities in one or more of the STAs. For example, the MU-RTS frame 1020 can use a poor user info field with a first AID 1034 and corresponding CTS feedback required information (CTSFR) 1036. THE AID 1034 can indicate that the user info field is for HE STA 504.1. The CTSFR 1036 can indicate that CTS feedback is required by STA 504.1 during the TXOP 1016. Accordingly, the STA 504.1 can transmit a CTS frame 1024 at operation 1012 and then receive data transmission of HE PPDU 1022.

[00106] The MU-RTS 1020 further includes power save information for AID 1038, which relates to STA 504.2. More specifically, the MU-RTS 1020 includes CTSFR 1040 indicating that a CTS feedback is not required from STA 504.2. Additionally, the MU-RTS 1020 include scheduling time target (STT) information 1042. The STT 1042 can indicate a specific time Tl within the TXOP 1016, which is a time when the STA 504.2 will be triggered or addressed by the AP 502. In this regard, the STA 504.2 can remain awake (at 1026) until time Tl and then listen (at 1028) for a data transmission from the AP 502.

[00107] In an example, STA 504.3 can determine that its AID is not listed within the MU-RTSs 1020. In this case, the STA 504.3 can activate a power save or sleep mode 1030 for the remainder of the TXOP 1016. Alternatively, the MU-RTS 1020 can indicate that STA 504.3 will not be addressed or triggered during the TXOP 1016. At the TXOP 1016 and, and at operation 1014, STA 504.3 can deactivate the power save or sleep mode and enter a regular operating mode 1032 in order to listen for a transmission from the AP 502.

[00108] In an example, the MU-RTS 1020 can be a power save announce control frame, which can be transmitted periodically (e.g., together with a beacon frame). For example, the announce frame 1020 can be transmitted at the period of the beacon frame, such as every 100 ms. In this regard, a service period of 100 ms can be defined, which is the period between two successive announcement frames. The announcement frame 1020 can include information as described herein in reference to FIG. 9. [00109] FIG. 11 illustrates a method TXOP announcement for TXOP power save in accordance with some embodiments. Referring to FIG. 11, the example method 1100 may start at 1 102, when a multiple user request-to-send (MU-RTS) high efficiency (HE) physical -layer convergence procedure (PLCP) protocol data unit (PPDU) can be decoded (e.g., by a processing circuitry of a wireless device). For example, STA 504.1 can decode the MU-RTS 1020 associ ated with the TXOP 1016. The MU-RTS 1020 can include duration information of a transmission opportunity (e.g., duration for TXOP 1016). The MU-RTS 1020 can also include a first plurality of association identifiers (AIDs) of wireless stations (STAs) which will be addressed or triggered duri ng the TXOP (e.g., AID1 for STA 504.1), and a second plurality of AIDs of STAs which will not be addressed or triggered during the TXOP (e.g., AID6 of STA 504.3). At 1104, the processing circuitry within the wireless device can determine whether the AID is within the first plurality of AIDs or within the second plurality of AIDs. At 1106, in response to determining the AID of the wireless device is within the second plurality of AIDs (e.g., AID6 of STA 504.3 can be within the second plurality of AIDs of STAs that will not be addressed during the TXOP), a power save mode can be activated for a remainder of the TXOP (as seen in FIG. 10).

[00110] FIG. 12 illustrates a method for power save announcement using a power save announce control frame (PSACF) in accordance with some embodiments. Referring to FIG. 12, the example method 1200 may start at 1202 when a power- save announce control frame (PSACF) is decoded at a wireless device. The PSACF (e.g., 900) is received periodically, once during a service period, which can be the period of a beacon frame used for transmission of the PSACF. The PSACF can include information (e.g., 904) identifying a first plurality of association identifiers (AIDs) of wireless stations (STAs) within the BSS, that are not be addressed or triggered within the service period. The

PSACF can also include information (e.g., 906) identifying a second plurality of AIDs of STAs within the BSS, that are addressed or triggered within the service period.

[00111] At 1204, processing circuitry at the wireless device can determine whether an AID of the wireless device is within the first plurality of AIDs or the second plurality of AIDs. At 1206, when it is determined that the AID of the wireless device is within the first plurality of AIDs, a power save mode of the wireless device can be activated for a remainder of the service period. At 1206, when it is determined that the AID of the wireless device is within the second plurality of AIDs, a normal operating mode of the wireless device can be maintained (or activated) for a remainder of the service period

[00112] FIG. 13 illustrates an HE station in accordance with some embodiments. HEW device 1300 may be an HEW compliant device that may be arranged to communicate with one or more other HEW devices, such as HEW devices 504 or access point 502 (FIG. 5) as well as communicate with legacy devices 506 (FIG. 5). HEW devices 504 and legacy devices 506 may also be referred to as HEW stations (STAs) and legacy STAs, respectively. HEW device 1300 may be suitable for operating as access point 502 (FIG. 5) or an HEW device 504 (FIG. 5). [00113] In accordance with embodiments, HEW device 1300 may include, among other things, a transmit/receive element 1301 (for example, an antenna), a transceiver 1302, PHY circuitry 1304, and MAC 1306. PHY 1304 and MAC 1306 may be HEW compliant layers and may also be compliant with one or more legacy IEEE 802.11 standards. MAC 1306 may be arranged to configure PPDUs and arranged to transmit and receive PPDUs, among other things. HEW device 1300 may also include other processing hardware circuitry 1308 and memory 1310 both of which may be configured to perform the various operations described herein. The hardware circuitry 1308 may be coupled to the transceiver 1302, which may be coupled to the transmit/receive element 1301. While FIG. 13 depicts the hardware circuitry 1308 and the transceiver 1302 as separate components, the hardware circuitry 1308 and the transceiver 1302 may be integrated together in an electronic package or chip. For example, the hardware circuitry and the transceiver 1302 can be part of a wireless circuit card, such as 102 in FIGS. 1 -4.

[00114] In example embodiments, the HEW device 1200 is configured to perform one or more of the functions and/or methods described herein in conjunction with FIGS. 5-14, such as using TXOP announcement for TXOP power save or using a power save announce frame for opportunistic power save (OPS).

[00115] The PHY 1304 may be arranged to transmit the HE PPDUusing the transceiver 1302. The PHY 1304 may include circuitry for

modulation/demodulation, upconversion/downconversion, filtering,

amplification, and so forth. For example, the PHY 1304 can include radio IC circuitry (e.g., 106A, 106B) and baseband processing circuitry (e.g., 108A, 108B). The transceiver 1302 can include front-end module circuitry (e.g., 104A, 104B in FIGS. 1 -4). [00116] In some embodiments, the hardware circuitry 1308 may include one or more processors. The hardware circuitry 1308 may be configured to perform functions based on instructions being stored in a random access memory (RAM) or read-only memory (ROM), or based on special purpose circuitry. In some embodiments, the hardware circuitry 1208 may be configured to perform one or more of the functions and/or methods described herein in conjunction with FIGS. 5-14, such as using TXOP announcement for TXOP power save or using a power save announce frame for opportunistic power save (OPS).

[00117] In some embodiments, two or more antennas may be coupled to the PHY 1304 and arranged for sending and receiving signals including transmission of the HEW packets. The HEW device 1300 may include a transceiver 1302 to transmit and receive data such as HEW PPDU and packets that include an indication that the HEW device 1300 should adapt the channel contention settings according to settings included in the packet. The memory 1310 may store information for configuring the other circuitry to perform operations for one or more of the functions and/or methods described herein for methods of transmitting pilot carriers, interpreting received pilot carriers, and generati ng and interpreting indications of which methods of transmitting pilot carriers to use.

[00118] In some embodiments, the HEW device 1300 may be configured to communicate using OFDM and/or OFDMA communication signals over a multicarrier communication channel. In some embodiments, HEW device 1300 may be configured to communicate in accordance with one or more specific communication standards, such as the IEEE standards including IEEE 802.11- 2012, 802.1 ln-2009, 802.1 lac-2013, 802.1 lax, standards and/or proposed specifications for WLANs, although the scope of the example embodiments is not limited in this respect as they may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. In some embodiments, the HEW device 1300 may use 4x symbol duration of 802.1 In or 802.1 lac.

[00119] In some embodiments, an HEW device 1300 may be part of a portable wireless communication device, such as a personal digital assistant

(PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), an access point, a base station, a transmit/receive device for a wireless standard such as 802.11 or 802.16, or other device that may receive and/or transmit information wirelessly. In some embodiments, the mobile device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be a liquid crystal display (LCD) screen including a touch screen. [00120] The transmit/receive element 1301 may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, phased antenna arrays, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of radio frequency (RF) signals. In some MIMO embodiments, the antennas may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

[00121] Although the device 1300 is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

[00122] FIG. 14 illustrates a block diagram of an example machine upon which any one or more of the techniques (e.g., methodologies) discussed herein may perform. In alternative embodiments, the communication device 1400 may operate as a standalone device or may be connected (e.g., networked) to other communication devices. In a networked deployment, the communication device 1400 may operate in the capacity of a server communication device, a client communication device, or both in server-client network environments. In an example, the communication device 1400 may act as a peer communication device in peer-to-peer (P2P) (or other distributed) network environment. The communication device 1400 may be a personal computer (PC), a tablet PC, a set top box (STB), a personal digital assistant (PDA), a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any

communication device capable of executing instructions (sequential or otherwise) that specify actions to be taken by that communication device. Further, while only a single communication device is illustrated, the term "communication device" shall also be taken to include any collection of communication devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[00123] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a communication device readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. [00124] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general -purpose hardware processor configured using software, the general -purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time. [00125] Communication device 1400 may include a hardware processor 1402 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 1404 and a static memory 1406, some or all of which may communicate with each other via an interlink (e.g., bus) 1408. The communication device 1400 may further include a display unit 1410, an input device 1412 (e.g., a keyboard), and a user interface (UI) navigation device 1414 (e.g., a mouse). In an example, the display unit 1410, input device 1412, and UI navigation device 1414 may be a touch screen display. In an example, the input device 1412 may include a touchscreen, a microphone, a camera (e.g., a panoramic or high-resolution camera), physical keyboard, trackball, or other input devices.

[00126] The communication device 1400 may additionally include a storage device (e.g., drive unit) 1416, a signal generation device 1418 (e.g., a speaker, a projection device, or any other type of information output device), a network interface device 1420, and one or more sensors 1421, such as a global positioning system (GPS) sensor, compass, accelerometer, motion detector, or other sensor. The communication device 1400 may include an input/output controller 1428, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.) via one or more input/output ports.

[00127] The storage device 1416 may include a communication device (or machine) readable medium 1422, on which is stored one or more sets of data structures or instructions 1424 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. In an example, at least a portion of the software may include an operating system and/or one or more applications (or apps) implementing one or more of the functionalities described herein. The instructions 1424 may also reside, completely or at least partially, within the main memory 1404, within the static memory 1406, and/or within the hardware processor 1402 during execution thereof by the communication device 1400. In an example, one or any combination of the hardware processor 1402, the main memory 1404, the static memory 1406, or the storage device 1416 may constitute communication device (or machine) readable media.

[00128] While the communication device readable medium 1422 is illustrated as a single medium, the term "communication device readable medium" or "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 1424.

[00129] The term "communication device readable medium" or "machine- readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the communication device 1400 and that cause the communication device 1400 to perform any one or more of the techni ques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non- limiting communication device readable medium examples may include solid- state memories, and optical and magnetic media. Specific examples of communication device readable media may include: non- volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples,

communication device readable media may include non-transitory

communication device readable media. In some examples, communication device readable media may include communication device readable media that is not a transitory propagating signal. The term "communication device readable medium" or "machine-readable medium" do not include signals or carrier waves.

[00130] The instructions 1424 may further be transmitted or received over a communications network 1426 using a transmission medium via the network interface device 1420 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (LDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.9 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, among others.

[00131] In an example, the network interface device 1420 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 1426. In an example, the network interface device 1420 may include one or more wireless modems, such as a Bluetooth modem, a Wi-Fi modem or one or more modems or transceivers operating under any of the communication standards mentioned herein. In an example, the network interface device 1420 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), ΜΓΜΟ, or multiple-input single-output (MISO) techniques. In some examples, the network interface device 1420 may wirelessly communicate using Multiple User MEVIO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the communication device 1400, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[00132] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructi ons, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. [00133] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general -purpose hardware processor configured using software, the general -purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[00134] Some embodiments may be implemented fully or partial ly in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer-readable medium may include any tangible non- transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory, etc.

[00135] The following examples pertain to further embodiments: [00136] Example 1 is an apparatus of a wireless device configured to operate within a basic service set (BSS) associated with an access point (AP), the wireless device comprising: memory; and processing circuitry coupled to the memory, the processing circuitry configured to: decode a power-save announce control frame (PSACF), wherein the PSACF is received periodically, once during a service period, the PSACF comprising: information identifying a first plurality of association identifiers (AIDs) of wireless stations (STAs) of the BSS, the AIDs corresponding to the STAs that are not addressed or triggered within the service period; determine whether an AID of the wireless device is within the first plurality of AIDs; and in response to determining the AID of the wireless device is within the first plurality of AIDs, acti vate a power save mode for a remainder of the service period.

[00137] In Example 2, the subject matter of Example 1 optionally includes wherein the PSACF comprises: information identifying a second plurality of AIDs of STAs of the BSS, the AIDs corresponding to the STAs that are addressed or triggered within the service period. [00138] In Example 3, the subject matter of Example 2 optionally includes wherein the processing circuitry configured to: in response to determining the AID of the wireless device is within the second plurality of AIDs, maintain a normal operating mode for the remainder of the service period.

[00139] In Example 4, the subject matter of any one or more of Examples 2-3 optionally include wherein the information identifying the first plurality of AIDs comprises a first bitmap, and the information identifying the second plurality of AIDs comprises a second bitmap.

[00140] In Example 5, the subject matter of Example 4 optionally includes wherein the first bitmap and the second bitmap are bitmaps in a traffic indication map (TIM) element.

[00141] In Example 6, the subject matter of any one or more of Examples 1-5 optionally include wherein the PSACF comprises information identifying a trigger frame and a target time for transmission of the trigger frame, and wherein the processing circuitry configured to: decode the trigger frame received at the target time. [00142] In Example 7, the subject matter of Example 6 optionally includes wherein the trigger frame is one of: a trigger frame that solicits an OFDMA random access frame; and a trigger frame that solicits a short PHY- feedback. [00143] In Example 8, the subject matter of any one or more of Examples 1-7 optionally include wherein the PSACF is a traffic indication map (TIM) frame.

[00144] In Example 9, the subject matter of any one or more of Examples 1-8 optionally include wherein the PSACF is a fast initial link setup (FILS) frame.

[00145] In Example 10, the subject matter of any one or more of

Examples 1-9 optionally include transceiver circuitry coupled to the memory; and one or more antennas coupled to the transceiver circuitry, wherein the transceiver circuitry is configured to receive the PSACF from an opportunistic power save (OPS) access point (AP) with a beacon frame.

[00146] In Example 11, the subject matter of any one or more of

Examples 1—10 optionally include wherein the processing circuitry is configured to: enable opportunistic power save (OPS) functionalities associated with the PSACF based on a target wake time (TWT) element received from an access point (AP).

[00147] In Example 12, the subject matter of Example 1 1 optionally includes wherein the processing circuitry is configured to: set a periodic broadcast TWT based on the received TWT element to enable the OPS functionalities. [00148] Example 13 is an apparatus of a wireless device comprising: memory; and processing circuitry coupled to the memory, the processing circuitry configured to: decode a high efficiency (HE) physical -layer convergence procedure (PLCP) protocol data unit (PPDU) comprising: duration information of a transmission opportunity (TXOP); association identifiers (AIDs) of wireless stations (STAs), which will be addressed or triggered during the TXOP; and feedback response information for each of the AIDs, the feedback response information indicating whether a response packet is required from a corresponding STA receiving the HE PPDU; determine whether the AIDs include an AID of the wireless device; and in response to determining the AIDs include the AID of the wireless device, encode, for transmission, the response packet based on the feedback response information corresponding to the AID of the wireless device.

[00149] In Example 14, the subject matter of Example 13 optionally includes wherein the TXOP duration information is in a media access control (MAC) portion of the HE PPDU. [00150] In Example 15, the subject matter of any one or more of

Examples 13-14 optionally include wherein the wireless device is within a basic service set (BSS) associated with an access point (AP), and wherein the HE PPDU is a multi-user request-to- send (MU-RTS) frame received from the AP and soliciting a response from the wireless device and at least another wireless device within the BSS.

[00151] In Example 16, the subject matter of any one or more of

Examples 13-15 optionally include wherein the response packet is a clear-to- send (CTS) response packet.

[00152] In Example 17, the subject matter of any one or more of

Examples 13-16 optionally include wherein the processing circuitry is configured to: in response to determining the AIDs do not include the AID of the wireless device, activate a power save mode for a duration of the TXOP.

[00153] In Example 18, the subject matter of any one or more of

Examples 13-17 optionally include wherein the HE PPDU is a multi-user request-to-send (MU-RTS) frame, and the TXOP duration information is within a common info field of the MU-RTS frame.

[00154] In Example 19, the subject matter of any one or more of

Examples 13-18 optionally include wherein the HE PPDU comprises a plurality of user info fields, each user info field comprising: an AID subfield indicating a corresponding one of the AIDs; and a resource unit (RU) subfield storing the feedback response information for the corresponding one of the ADIs. [00155] In Example 20, the subject matter of Example 19 optionally includes wherein: an AID subfield for one of the plurality of user info fields comprises a group ID indicating at least two of the STAs; and the feedback response information within the RU subfield for the one of the plurality of user info fields is associated with the at least two of the STAs.

[00156] In Example 21, the subject matter of any one or more of Examples 13-20 optionally include wherein the HE PPDU comprises a plurality of user info fields, each user info field comprising at least one reserved subfield storing the feedback response information. [00157] In Example 22, the subject matter of Example 21 optionally includes wherein the at least one reserved subfield is one of: a coding type subfield; a spatial streams (SS) allocation subfield; or a target RSSI subfield.

[00158] In Example 23, the subject matter of any one or more of Examples 13-22 optionally include wherein the processing circuitry is configured to: in response to determining the AIDs include the AID of the wireless device and the feedback response information for the wireless device indicates the response packet is not required, refrain from transmitting the response packet during the TXOP.

[00159] In Example 24, the subject matter of any one or more of Examples 13-23 optionally include wherein the processing circuitry is configured to: decode the HE PPDU to obtain scheduling time target (STT) information, the STT information indicating a time within the TXOP when the wireless device will be addressed or triggered.

[00160] In Example 25, the subject matter of Example 24 optionally includes wherein the STT information further indicates a time within the TXOP when at least another STA of the STAs will be addressed or triggered.

[00161] In Example 26, the subject matter of any one or more of Examples 24-25 optionally include wherein the STT information for each of the STAs is stored within a plurality of user info fields of the HE PPDU. [00162] In Example 27, the subject matter of Example 26 optionally includes wherein the STT information for each of the STAs is stored within a coding type subfield, a spatial streams (SS) allocation subfield, or a target RSSI subfield within each of the plurality of user info fields.

[00163] In Example 28, the subject matter of any one or more of

Examples 13-27 optionally include transceiver circuitry coupled to the memory; and one or more antennas coupled to the transceiver circuitry.

[00164] Example 29 is an apparatus of a wireless device comprising: memory; and processing circuitry coupled to the memory, the processing circuitry configured to: decode a multiple user request-to-send (MU-RTS) high efficiency (HE) physical -layer convergence procedure (PLCP) protocol data unit (PPDU) comprising: duration information of a transmission opportunity

(TXOP); and a first plurality of association identifiers (AIDs) of wireless stations (STAs) which will be addressed or triggered during the TXOP, and a second plurality of AIDs of STAs which will not be addressed or triggered during the TXOP; determine whether the AID of the wireless device is within the first plurality of AIDs or within the second plurality of AIDs; and in response to determining the AID of the wireless device is within the second plurality of AIDs, acti vate a power save mode for a remainder of the TXOP.

[00165] In Example 30, the subject matter of Example 29 optionally includes wherein the processing circuitry is configured to: decode the HE PPDU to determine a TXOP identifier of a subsequent TXOP when the wireless device will be addressed or triggered, the TXOP identifier including a future time when the subsequent TXOP begins.

[00166] In Example 31, the subject matter of Example 30 optionally includes wherein the processing circuitry is configured to: deactivate the power save mode and initiate a normal operating mode at the indicated future time.

[00167] In Example 32, the subject matter of any one or more of

Examples 30-31 optionally include wherein the TXOP identifier is within a reserved bit of a user info field of a plurality of user info fields in the MU- RTS PPDU, the user info field associated with the wireless device. [00168] In Example 33, the subject matter of Example 32 optionally includes wherein the reserved bit is within one of: a dual carrier modulation subfield of the user info field; a spatial streams (SS) allocation subfield of the user info field; or a target RSSI subfield of the user info field.

[00169] In Example 34, the subject matter of any one or more of

Examples 29-33 optionally include wherein the processing circuitry is configured to, in response to determining the AID of the wireless deviceis within the first plurality of AIDs: decode the MU-RTS PPDU to obtain scheduling time target (STT) information, the STT information indicating a time within the TXOP when the wireless device will be addressed or triggered.

[00170] In Example 35, the subject matter of Example 34 optionally includes wherein the STT information is stored within one of a plurality of user info fields of the MU-RTS PPDU.

[00171] In Example 36, the subject matter of Example 35 optionally includes wherein the STT information is stored within a coding type subfield, a spatial streams (SS) allocation subfield, or a target RSSI subfield within the one of the plurality of user info fields.

[00172] Example 37 is an apparatus of an access point (AP) comprising: memory; and processing circuitry coupled to the memory, the processing circuitry configured to: encode a multi-user (MU) request-to-send (RTS) frame comprising: duration information of a transmission opportunity (TXOP);

association identifiers (AIDs) of wireless stations (STAs), which will be addressed or triggered during the TXOP; and feedback response information for each of the AIDs, the feedback response information indicating whether a response packet is required from a corresponding STA receiving the HE PPDU; decode a clear-to-send (CTS) response frame from at least one of the STAs; and encode a high efficiency (HE) MU physical -layer convergence procedure (PLCP) protocol data unit (PPDU) for transmission to the STA during the TXOP.

[00173] Example 38 is a system configured to perform operations of any one or more of Examples 1-37. [00174] Example 39 is a method for performing operations of any one or more of Examples 1-37. [00175] Example 40 is a machine readable medium including instructions that, when executed by a machine cause the machine to perform the operations of any one or more of Examples 1-37.

[00176] Example 41 is a system comprising means for performing the operations of any one or more of Examples 1-37.

[00177] Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods.

[00178] Any of the computer-executable instructions for implementing the disclosed techniques as well as any data created and used during

implementation of the disclosed embodiments can be stored on one or more computer-readable storage media. The computer-executable instructions can be part of, for example, a dedicated software application or a software application that is accessed or downloaded via a web browser or other software application (such as a remote computing application). Such software can be executed, for example, on a single local computer (e.g., any suitable commercially available computer) or in a network environment (e.g., via the Internet, a wide-area network, a local-area network, a client-server network (such as a cloud computing network), or other such network) using one or more network computers.

[00179] The disclosed methods, apparatus, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub combinations with one another. The disclosed methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.

[00180] Publicati ons, patents, and patent documents referred to in thi s document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) are supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls. [00181] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with others. Other embodiments may be used, such as by one of ordinary skill in the art upon reviewing the above description. [00182] The Ab stract i s provi ded to al 1 ow the reader to ascertai n the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. However, the claims may not set forth every feature disclosed herein as embodiments may feature a subset of said features. Further, embodiments may include fewer features than those disclosed in a particular example. Thus, the following claims are hereby incorporated into the Detailed Description, with a claim standing on its own as a separate embodiment. The scope of the embodiments disclosed herein is to be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.