TIME-SYNCHRONIZATION FOR TRIGGER-BASED WLAN SENSING USING PARTIAL TSF INFORMATION FROM SENSING SOUNDING TRIGGER FRAME

A non-access point station (STA) configured for performing wireless local area network (WLAN) sensing may be configured to update its time-synchronization function (TSF) based on partial TSF information when a sensing poll trigger frame (TF) and the sensing sounding TF are received in a same sensing measurement instance when the sensing sounding TF includes a special user information field containing the partial TSF information.

TECHNICAL FIELD

Embodiments pertain to wireless communications. Some embodiments pertain to wireless networks including wireless local area networks (WLANs) and Wi-Fi networks including networks operating in accordance with the IEEE 802.11 family of standards. Some embodiments relate to extremely high throughput (EHT) communications. Some embodiments pertain to WLAN sensing in accordance with draft standard IEEE P802.11bf.

BACKGROUND

WLAN sensing is the use of PHY and MAC features of IEEE 802.11 stations to obtain measurements that may be useful to estimate features such as range, velocity, and motion of objects in an area of interest. Measurements obtained with WLAN sensing may be used to enable applications such as presence detection and gesture classification. One issue with WLAN sensing is that a station (STA) may not track the time synchronization function (TSF) of the access point (AP). As a result, the time windows may not align due to clock drift. Thus, what is needed is a way to improve synchronization of the TSF of a STA and an AP for WLAN sensing.

DETAILED DESCRIPTION

Sensing is the use of PHY and MAC features of IEEE 802.11 stations to obtain measurements that may be useful to estimate features such as range, velocity, and motion of objects in an area of interest. Measurements obtained with WLAN sensing may be used to enable applications such as presence detection and gesture classification.

Embodiments disclosed herein relate to time synchronization for trigger-based (TB) WLAN sensing. Some embodiments disclosed herein may help resolve a time synchronization issue with minimal changes to the TB sensing measurement sequence. These embodiments are described in more detail herein.

Embodiments are directed to time synchronization for trigger-based (TB) sensing. Some embodiments are directed to a non-access point station (STA) configured for performing wireless local area network (WLAN) sensing. In these embodiments, the STA may be configured to update its time-synchronization function (TSF) based on partial TSF information when a sensing poll trigger frame (TF) and the sensing sounding TF are received in a same sensing measurement instance when the sensing sounding TF includes a special user information field containing the partial TSF information. These embodiments, as well as others, are discussed in more detail below.

FIG.1is a block diagram of a radio architecture100in accordance with some embodiments. Radio architecture100may include radio front-end module (FEM) circuitry104, radio IC circuitry106and baseband processing circuitry108. Radio architecture100as shown includes both Wireless Local Area Network (WLAN) functionality and Bluetooth (BT) functionality although embodiments are not so limited. In this disclosure, “WLAN” and “Wi-Fi” are used interchangeably.

FEM circuitry104may include a WLAN or Wi-Fi FEM circuitry104A and a Bluetooth (BT) FEM circuitry104B. The WLAN FEM circuitry104A may include a receive signal path comprising circuitry configured to operate on WLAN RF signals received from one or more antennas101, to amplify the received signals and to provide the amplified versions of the received signals to the WLAN radio IC circuitry106A for further processing. The BT FEM circuitry104B may include a receive signal path which may include circuitry configured to operate on BT RF signals received from one or more antennas101, to amplify the received signals and to provide the amplified versions of the received signals to the BT radio IC circuitry106B for further processing. FEM circuitry104A may also include a transmit signal path which may include circuitry configured to amplify WLAN signals provided by the radio IC circuitry106A for wireless transmission by one or more of the antennas101. In addition, FEM circuitry104B may also include a transmit signal path which may include circuitry configured to amplify BT signals provided by the radio IC circuitry106B for wireless transmission by the one or more antennas. In the embodiment ofFIG.1, although FEM104A and FEM104B are shown as being distinct from one another, embodiments 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.

Radio IC circuitry106as shown may include WLAN radio IC circuitry106A and BT radio IC circuitry106B. The WLAN radio IC circuitry106A may include a receive signal path which may include circuitry to down-convert WLAN RF signals received from the FEM circuitry104A and provide baseband signals to WLAN baseband processing circuitry108A. BT radio IC circuitry106B may in turn include a receive signal path which may include circuitry to down-convert BT RF signals received from the FEM circuitry104B and provide baseband signals to BT baseband processing circuitry108B. WLAN radio IC circuitry106A may also include a transmit signal path which may include circuitry to up-convert WLAN baseband signals provided by the WLAN baseband processing circuitry108A and provide WLAN RF output signals to the FEM circuitry104A for subsequent wireless transmission by the one or more antennas101. BT radio IC circuitry106B may also include a transmit signal path which may include circuitry to up-convert BT baseband signals provided by the BT baseband processing circuitry108B and provide BT RF output signals to the FEM circuitry104B for subsequent wireless transmission by the one or more antennas101. In the embodiment ofFIG.1, although radio IC circuitries106A and106B are shown as being distinct from one another, embodiments 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.

Baseband processing circuitry108may include a WLAN baseband processing circuitry108A and a BT baseband processing circuitry108B. The WLAN baseband processing circuitry108A 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 circuitry108A. Each of the WLAN baseband circuitry108A and the BT baseband circuitry108B 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 circuitry106, and to also generate corresponding WLAN or BT baseband signals for the transmit signal path of the radio IC circuitry106. Each of the baseband processing circuitries108A and108B may further include physical layer (PHY) and medium access control layer (MAC) circuitry, and may further interface with application processor111for generation and processing of the baseband signals and for controlling operations of the radio IC circuitry106.

Referring still toFIG.1, according to the shown embodiment, WLAN-BT coexistence circuitry113may include logic providing an interface between the WLAN baseband circuitry108A and the BT baseband circuitry108B to enable use cases requiring WLAN and BT coexistence. In addition, a switch103may be provided between the WLAN FEM circuitry104A and the BT FEM circuitry104B to allow switching between the WLAN and BT radios according to application needs. In addition, although the antennas101are depicted as being respectively connected to the WLAN FEM circuitry104A and the BT FEM circuitry104B, embodiments 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 FEM104A or104B.

In some embodiments, the front-end module circuitry104, the radio IC circuitry106, and baseband processing circuitry108may be provided on a single radio card, such as wireless radio card102. In some other embodiments, the one or more antennas101, the FEM circuitry104and the radio IC circuitry106may be provided on a single radio card. In some other embodiments, the radio IC circuitry106and the baseband processing circuitry108may be provided on a single chip or IC, such as IC112.

In some embodiments, the radio architecture100may be configured for high-efficiency (HE) Wi-Fi (HEW) communications in accordance with the IEEE 802.11ax standard. In these embodiments, the radio architecture100may be configured to communicate in accordance with an OFDMA technique, although the scope of the embodiments is not limited in this respect.

In some embodiments, as further shown inFIG.1, the BT baseband circuitry108B 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 embodiments that include BT functionality as shown for example inFIG.1, the radio architecture100may be configured to establish a BT synchronous connection oriented (SCO) link and/or a BT low energy (BT LE) link. In some of the embodiments that include functionality, the radio architecture100may be configured to establish an extended SCO (eSCO) link for BT communications, although the scope of the embodiments is not limited in this respect. In some of these embodiments 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 embodiments is not limited in this respect. In some embodiments, as shown inFIG.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 card102, although embodiments are not so limited, and include within their scope discrete WLAN and BT radio cards

In some embodiments, the radio-architecture100may include other radio cards, such as a cellular radio card configured for cellular (e.g., 3GPP such as LTE, LTE-Advanced or 5G communications).

In some IEEE 802.11 embodiments, the radio architecture100may 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, 5 MHz, 8 MHz, 10 MHz, 16 MHz, 20 MHz, 40 MHz, 80 MHz (with contiguous bandwidths) or 80+80 MHz (160 MHz) (with non-contiguous bandwidths). In some embodiments, a 320 MHz channel bandwidth may be used. The scope of the embodiments is not limited with respect to the above center frequencies however.

FIG.2illustrates FEM circuitry200in accordance with some embodiments. The FEM circuitry200is one example of circuitry that may be suitable for use as the WLAN and/or BT FEM circuitry104A/104B (FIG.1), although other circuitry configurations may also be suitable.

In some embodiments, the FEM circuitry200may include a TX/RX switch202to switch between transmit mode and receive mode operation. The FEM circuitry200may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry200may include a low-noise amplifier (LNA)206to amplify received RF signals203and provide the amplified received RF signals207as an output (e.g., to the radio IC circuitry106(FIG.1)). The transmit signal path of the circuitry200may include a power amplifier (PA) to amplify input RF signals209(e.g., provided by the radio IC circuitry106), and one or more filters212, such as band-pass filters (BPFs), low-pass filters (LPFs) or other types of filters, to generate RF signals215for subsequent transmission (e.g., by one or more of the antennas101(FIG.1)).

In some dual-mode embodiments for Wi-Fi communication, the FEM circuitry200may be configured to operate in either the 2.4 GHz frequency spectrum or the 5 GHz frequency spectrum. In these embodiments, the receive signal path of the FEM circuitry200may include a receive signal path duplexer204to separate the signals from each spectrum as well as provide a separate LNA206for each spectrum as shown. In these embodiments, the transmit signal path of the FEM circuitry200may also include a power amplifier210and a filter212, such as a BPF, a LPF or another type of filter for each frequency spectrum and a transmit signal path duplexer214to provide the signals of one of the different spectrums onto a single transmit path for subsequent transmission by the one or more of the antennas101(FIG.1). In some embodiments, BT communications may utilize the 2.4 GHZ signal paths and may utilize the same FEM circuitry200as the one used for WLAN communications.

FIG.3illustrates radio integrated circuit (IC) circuitry300in accordance with some embodiments. The radio IC circuitry300is one example of circuitry that may be suitable for use as the WLAN or BT radio IC circuitry106A/106B (FIG.1), although other circuitry configurations may also be suitable.

In some embodiments, the radio IC circuitry300may include a receive signal path and a transmit signal path. The receive signal path of the radio IC circuitry300may include at least mixer circuitry302, such as, for example, down-conversion mixer circuitry, amplifier circuitry306and filter circuitry308. The transmit signal path of the radio IC circuitry300may include at least filter circuitry312and mixer circuitry314, such as, for example, up-conversion mixer circuitry. Radio IC circuitry300may also include synthesizer circuitry304for synthesizing a frequency305for use by the mixer circuitry302and the mixer circuitry314. The mixer circuitry302and/or314may each, according to some embodiments, 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.3illustrates only a simplified version of a radio IC circuitry, and may include, although not shown, embodiments where each of the depicted circuitries may include more than one component. For instance, mixer circuitry320and/or314may each include one or more mixers, and filter circuitries308and/or312may 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.

In some embodiments, mixer circuitry302may be configured to down-convert RF signals207received from the FEM circuitry104(FIG.1) based on the synthesized frequency305provided by synthesizer circuitry304. The amplifier circuitry306may be configured to amplify the down-converted signals and the filter circuitry308may include a LPF configured to remove unwanted signals from the down-converted signals to generate output baseband signals307. Output baseband signals307may be provided to the baseband processing circuitry108(FIG.1) for further processing. In some embodiments, the output baseband signals307may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry302may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry314may be configured to up-convert input baseband signals311based on the synthesized frequency305provided by the synthesizer circuitry304to generate RF output signals209for the FEM circuitry104. The baseband signals311may be provided by the baseband processing circuitry108and may be filtered by filter circuitry312. The filter circuitry312may include a LPF or a BPF, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry302and the mixer circuitry314may each include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion respectively with the help of synthesizer304. In some embodiments, the mixer circuitry302and the mixer circuitry314may each include two or more mixers each configured for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry302and the mixer circuitry314may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuitry302and the mixer circuitry314may be configured for super-heterodyne operation, although this is not a requirement.

Mixer circuitry302may 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 signal207fromFIG.3may be down-converted to provide I and Q baseband output signals to be sent to the baseband processor

In some embodiments, 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 embodiments, the LO signals may have a 25% duty cycle and a 50% offset. In some embodiments, 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.

The RF input signal207(FIG.2) may comprise a balanced signal, although the scope of the embodiments is not limited in this respect. The I and Q baseband output signals may be provided to low-nose amplifier, such as amplifier circuitry306(FIG.3) or to filter circuitry308(FIG.3).

In some embodiments, the output baseband signals307and the input baseband signals311may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals307and the input baseband signals311may be digital baseband signals. In these alternate embodiments, the radio IC circuitry may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry.

In some embodiments, the synthesizer circuitry304may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry304may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. According to some embodiments, the synthesizer circuitry304may 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 embodiments, frequency input into synthesizer circuitry304may 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 circuitry108(FIG.1) or the application processor111(FIG.1) depending on the desired output frequency305. In some embodiments, 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 processor111.

In some embodiments, synthesizer circuitry304may be configured to generate a carrier frequency as the output frequency305, while in other embodiments, the output frequency305may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some embodiments, the output frequency305may be a LO frequency (fLO).

FIG.4illustrates a functional block diagram of baseband processing circuitry400in accordance with some embodiments. The baseband processing circuitry400is one example of circuitry that may be suitable for use as the baseband processing circuitry108(FIG.1), although other circuitry configurations may also be suitable. The baseband processing circuitry400may include a receive baseband processor (RX BBP)402for processing receive baseband signals309provided by the radio IC circuitry106(FIG.1) and a transmit baseband processor (TX BBP)404for generating transmit baseband signals311for the radio IC circuitry106. The baseband processing circuitry400may also include control logic406for coordinating the operations of the baseband processing circuitry400.

In some embodiments (e.g., when analog baseband signals are exchanged between the baseband processing circuitry400and the radio IC circuitry106), the baseband processing circuitry400may include ADC410to convert analog baseband signals received from the radio IC circuitry106to digital baseband signals for processing by the RX BBP402. In these embodiments, the baseband processing circuitry400may also include DAC412to convert digital baseband signals from the TX BBP404to analog baseband signals.

FIG.5illustrates a WLAN500in accordance with some embodiments. The WLAN500may comprise a basis service set (BSS) that may include an access point (AP)502, a plurality of stations (STAs)504, and a plurality of legacy devices506. In some embodiments, the STAs504and/or AP502are configured to operate in accordance with IEEE 802.11be extremely high throughput (EHT) and/or high efficiency (HE) IEEE 802.11ax. In some embodiments, the STAs504and/or AP520are configured to operate in accordance with IEEE 802.11az. In some embodiments, IEEE 802.11EHT may be termed Next Generation 802.11 or a later standard. The STA504and AP502(or apparatuses of) may be configured to operate in accordance with IEEE P802.11be™/D2.2, October 2022, IEEE P802.11-REVme™/D2.0, October 2022, which are incorporated herein by reference in their entirety. The AP502and/or STA504may operate in accordance with different versions of the communication standards.

The AP502may be an AP using the IEEE 802.11 to transmit and receive. The AP502may be a base station. The AP502may use other communications protocols as well as the IEEE 802.11 protocol. The EHT protocol may be termed a different name in accordance with some embodiments. The IEEE 802.11 protocol may include using orthogonal frequency division multiple-access (OFDMA), time division 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 EHT AP502that is part of an extended service set (ESS). A controller (not illustrated) may store information that is common to the more than one APs502and may control more than one BSS, e.g., assign primary channels, colors, etc. AP502may be connected to the internet.

The legacy devices506may operate in accordance with one or more of IEEE 802.11 a/b/g/n/ac/ad/af/ah/aj/ay/ax/be, or another legacy wireless communication standard. The legacy devices506may be STAs or IEEE STAs. The STAs504may 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 802.11be or another wireless protocol.

The AP502may communicate with legacy devices506in accordance with legacy IEEE 802.11 communication techniques. In example embodiments, the H AP502may also be configured to communicate with STAs504in accordance with legacy IEEE 802.11 communication techniques.

In some embodiments, a HE or EHT frames may be configurable to have the same bandwidth as a channel. The HE or EHT frame may be a physical Layer (PHY) Protocol Data Unit (PPDU). In some embodiments, PPDU may be an abbreviation for physical layer protocol data unit (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. For example, a single user (SU) PPDU, multiple-user (MU) PPDU, extended-range (ER) SU PPDU, and/or trigger-based (TB) PPDU. In some embodiments EHT may be the same or similar as HE PPDUs.

The bandwidth of a channel may be 20 MHz, 40 MHz, or 80 MHz, 80+80 MHz, 160 MHz, 160+160 MHz, 320 MHz, 320+320 MHz, 640 MHz bandwidths. In some embodiments, the bandwidth of a channel less than 20 MHz 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, 106, 242, 484, 996, or 2×996 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.

In some embodiments, the 26-subcarrier RU 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-MIMO HE PPDU formats. In some embodiments, the 242-subcarrier RU 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-MIMO HE PPDU formats. In some embodiments, the 996-subcarrier RU is used in the 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. In some embodiments, two or more of the RUs are joined as an MRU.

A HE or EHT 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 AP502, STA504, and/or legacy device506may also implement different technologies such as code division multiple access (CDMA) 2000, CDMA 2000 1×, 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®, low-power BlueTooth®, or other technologies.

In accordance with some IEEE 802.11 embodiments, e.g., IEEE 802.11EHT/ax embodiments, a HE AP502may operate as a master station which may be arranged to contend for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium for a transmission opportunity (TXOP). The AP502may transmit an EHT/HE trigger frame transmission, which may include a schedule for simultaneous UL/DL transmissions from STAs504. The AP502may transmit a time duration of the TXOP and sub-channel information. During the TXOP, STAs504may communicate with the AP502in 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 or EHT control period, the AP502may communicate with STAs504using one or more HE or EHT frames. During the TXOP, the HE STAs504may operate on a sub-channel smaller than the operating range of the AP502. During the TXOP, legacy stations refrain from communicating. The legacy stations may need to receive the communication from the HE AP502to defer from communicating.

In accordance with some embodiments, during the TXOP the STAs504may contend for the wireless medium with the legacy devices506being 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 UL-MU-MIMO and/or DL OFDMA with a schedule indicated in a preamble portion of trigger frame.

In some embodiments, the multiple-access technique used during the HE or EHT 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-division multiple access (SDMA) technique. In some embodiments, the multiple access technique may be a Code division multiple access (CDMA).

The AP502may also communicate with legacy devices506and/or STAs504in accordance with legacy IEEE 802.11 communication techniques. In some embodiments, the AP502may also be configurable to communicate with STAs504outside the TXOP in accordance with legacy IEEE 802.11 or IEEE 802.11EHT/ax communication techniques, although this is not a requirement.

In some embodiments the STA504may be a “group owner” (GO) for peer-to-peer modes of operation. A wireless device may be a STA504or a HE AP502.

In some embodiments, the STA504and/or AP502may be configured to operate in accordance with IEEE 802.11mc. In example embodiments, the radio architecture ofFIG.1is configured to implement the STA504and/or the AP502. In example embodiments, the front-end module circuitry ofFIG.2is configured to implement the STA504and/or the AP502. In example embodiments, the radio IC circuitry ofFIG.3is configured to implement the STA504and/or the AP502. In example embodiments, the base-band processing circuitry ofFIG.4is configured to implement the STA504and/or the AP502.

In example embodiments, the STAs504, AP502, an apparatus of the STA504, and/or an apparatus of the AP502may include one or more of the following: the radio architecture ofFIG.1, the front-end module circuitry ofFIG.2, the radio IC circuitry ofFIG.3, and/or the base-band processing circuitry ofFIG.4.

In example embodiments, the radio architecture ofFIG.1, the front-end module circuitry ofFIG.2, the radio IC circuitry ofFIG.3, and/or the base-band processing circuitry ofFIG.4may be configured to perform the methods and operations/functions described herein.

In example embodiments, the STAs504and/or the HE AP502are configured to perform the methods and operations/functions described herein. In example embodiments, an apparatus of the STA504and/or an apparatus of the AP502are configured to perform the methods and functions described herein. The term Wi-Fi may refer to one or more of the IEEE 802.11 communication standards. AP and STA may refer to EHT/HE access point and/or EHT/HE station as well as legacy devices506.

In some embodiments, a HE AP STA may refer to an AP502and/or STAs504that are operating as EHT APs502. In some embodiments, when a STA504is not operating as an AP, it may be referred to as a non-AP STA or non-AP. In some embodiments, STA504may be referred to as either an AP STA or a non-AP. In some embodiments, the AP502is an AP of the AP MLD808. In some embodiments, the STA504is a STA of non-AP MLD 3809.

Machine (e.g., computer system)600may include a hardware processor602(e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory604and a static memory606, some or all of which may communicate with each other via an interlink (e.g., bus)608.

Specific examples of main memory604include Random Access Memory (RAM), and semiconductor memory devices, which may include, in some embodiments, storage locations in semiconductors such as registers. Specific examples of static memory606include 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; RAM; and CD-ROM and DVD-ROM disks.

The machine600may further include a display device610, an input device612(e.g., a keyboard), and a user interface (UI) navigation device614(e.g., a mouse). In an example, the display device610, input device612and UI navigation device614may be a touch screen display. The machine600may additionally include a mass storage (e.g., drive unit)616, a signal generation device618(e.g., a speaker), a network interface device620, and one or more sensors621, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine600may include an output controller628, 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.). In some embodiments the processor602and/or instructions624may comprise processing circuitry and/or transceiver circuitry.

Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., EPROM or EEPROM) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; RAM; and CD-ROM and DVD-ROM disks.

An apparatus of the machine600may be one or more of a hardware processor602(e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory604and a static memory606, sensors621, network interface device620, antennas660, a display device610, an input device612, a UI navigation device614, a mass storage616, instructions624, a signal generation device618, and an output controller628. The apparatus may be configured to perform one or more of the methods and/or operations disclosed herein. The apparatus may be intended as a component of the machine600to perform one or more of the methods and/or operations disclosed herein, and/or to perform a portion of one or more of the methods and/or operations disclosed herein. In some embodiments, the apparatus may include a pin or other means to receive power. In some embodiments, the apparatus may include power conditioning hardware.

In an example, the network interface device620may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network626. In an example, the network interface device620may include one or more antennas660to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. In some examples, the network interface device620may wirelessly communicate using Multiple User MIMO 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 machine600, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

FIG.7illustrates a block diagram of an example wireless device700upon which any one or more of the techniques (e.g., methodologies or operations) discussed herein may perform. The wireless device700may be a HE device or HE wireless device. The wireless device700may be a HE STA504, HE AP502, and/or a HE STA or HE AP. A HE STA504, HE AP502, and/or a HE AP or HE STA may include some or all of the components shown inFIGS.1-7. The wireless device700may be an example machine600as disclosed in conjunction withFIG.6.

The wireless device700may include processing circuitry708. The processing circuitry708may include a transceiver702, physical layer circuitry (PHY circuitry)704, and MAC layer circuitry (MAC circuitry)706, one or more of which may enable transmission and reception of signals to and from other wireless devices700(e.g., HE AP502, HE STA504, and/or legacy devices506) using one or more antennas712. As an example, the PHY circuitry704may perform various encoding and decoding functions that may include formation of baseband signals for transmission and decoding of received signals. As another example, the transceiver702may perform various transmission and reception functions such as conversion of signals between a baseband range and a Radio Frequency (RF) range.

Accordingly, the PHY circuitry704and the transceiver702may be separate components or may be part of a combined component, e.g., processing circuitry708. In addition, some of the described functionality related to transmission and reception of signals may be performed by a combination that may include one, any or all of the PHY circuitry704the transceiver702, MAC circuitry706, memory710, and other components or layers. The MAC circuitry706may control access to the wireless medium. The wireless device700may also include memory710arranged to perform the operations described herein, e.g., some of the operations described herein may be performed by instructions stored in the memory710.

One or more of the memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712, and/or the processing circuitry708may be coupled with one another. Moreover, although memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712are illustrated as separate components, one or more of memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712may be integrated in an electronic package or chip.

In some embodiments, the wireless device700may be a mobile device as described in conjunction withFIG.6. In some embodiments the wireless device700may be configured to operate in accordance with one or more wireless communication standards as described herein (e.g., as described in conjunction withFIGS.1-6, IEEE 802.11). In some embodiments, the wireless device700may include one or more of the components as described in conjunction withFIG.6(e.g., display device610, input device612, etc.) Although the wireless device700is 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.

In some embodiments, an apparatus of or used by the wireless device700may include various components of the wireless device700as shown inFIG.7and/or components fromFIGS.1-6. Accordingly, techniques and operations described herein that refer to the wireless device700may be applicable to an apparatus for a wireless device700(e.g., HE AP502and/or HE STA504), in some embodiments. In some embodiments, the wireless device700is configured to decode and/or encode signals, packets, and/or frames as described herein, e.g., PPDUs.

In some embodiments, the MAC circuitry706may be arranged to contend for a wireless medium during a contention period to receive control of the medium for a HE TXOP and encode or decode an HE PPDU. In some embodiments, the MAC circuitry706may be arranged to contend for the wireless medium based on channel contention settings, a transmitting power level, and a clear channel assessment level (e.g., an energy detect level).

The PHY circuitry704may be arranged to transmit signals in accordance with one or more communication standards described herein. For example, the PHY circuitry704may be configured to transmit a HE PPDU. The PHY circuitry704may include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry708may include one or more processors. The processing circuitry708may be configured to perform functions based on instructions being stored in a RAM or ROM, or based on special purpose circuitry. The processing circuitry708may include a processor such as a general purpose processor or special purpose processor. The processing circuitry708may implement one or more functions associated with antennas712, the transceiver702, the PHY circuitry704, the MAC circuitry706, and/or the memory710. In some embodiments, the processing circuitry708may be configured to perform one or more of the functions/operations and/or methods described herein.

In mmWave technology, communication between a station (e.g., the HE stations504ofFIG.5or wireless device700) and an access point (e.g., the HE AP502ofFIG.5or wireless device700) may use associated effective wireless channels that are highly directionally dependent. To accommodate the directionality, beamforming techniques may be utilized to radiate energy in a certain direction with certain beamwidth to communicate between two devices. The directed propagation concentrates transmitted energy toward a target device in order to compensate for significant energy loss in the channel between the two communicating devices. Using directed transmission may extend the range of the millimeter-wave communication versus utilizing the same transmitted energy in omni-directional propagation.

FIG.8illustrates multi-link devices (MLDs), in accordance with some embodiments. Illustrated inFIG.8is ML logical entity 1 or non-AP MLD 1806, ML logical entity 2 or non-AP MLD 2807, ML AP logical entity or AP MLD808, and ML non-AP logical entity or non-AP MLD 3809. The non-AP MLD 1806includes three STAs, STA1.1814.1, STA1.2814.2, and STA1.3814.3that operate in accordance with link 1802.1, link 2802.2, and link 3802.3, respectively. The Links are described below. Non-AP MLD 2807includes STA2.1816.1, STA2.2816.2, and STA2.3816.3that operate in accordance with link 1802.1, link 2802.2, and link 3802.3, respectively. In some embodiments non-AP MLD 1806and non-AP MLD 2807operate in accordance with a mesh network. Using three links enables the non-AP MLD 1806and non-AP MLD 2807to operate using a greater bandwidth and to operate more reliably as they can switch to using a different link if there is interference or if one link is superior due to operating conditions.

The distribution system (DS)810indicates how communications are distributed and the DS medium (DSM)812indicates the medium that is used for the DS810, which in this case is the wireless spectrum.

AP MLD808includes AP1830, AP2832, and AP3834operating on link 1802.1, link 2802.2, and link 3802.3, respectively. AP MLD808includes a MAC address854that may be used by applications to transmit and receive data across one or more of AP1830, AP2832, and AP3834.

AP1830, AP2832, and AP3834may operate different BSSIDs, which are BSSID842, BSSID844, and BSSID846, respectively. AP1830, AP2832, and AP3834include different media access control (MAC) address (addr), which are MAC adder848, MAC addr850, and MAC addr852, respectively. The AP502is an AP MLD808, in accordance with some embodiments. The STA504is a non-AP MLD 3809, in accordance with some embodiments.

The non-AP MLD 3809includes non-AP STA1818, non-AP STA2820, and non-AP STA3822. Each of the non-AP STAs have a MAC address (not illustrated) and the non-AP MLD 3809has a MAC address855that is different and used by application programs where the data traffic is split up among non-AP STA1818, non-AP STA2820, and non-AP STA3822.

The STA504is a non-AP STA1818, non-AP STA2820, or non-AP STA3822, in accordance with some embodiments. The non-AP STA1818, non-AP STA2820, and non-AP STA3822may operate as if they are associated with a BSS of AP1830, AP2832, or AP3834, respectively, over link 1804.1, link 2804.2, and link 3804.3, respectively.

A Multi-link device such as non-AP MLD 1806or non-AP MLD 2807, is a logical entity that contains one or more STAs814,816. The non-AP MLD 1806and non-AP MLD 2807each has one MAC data service interface and primitives to the logical link control (LLC) and a single address associated with the interface, which can be used to communicate on the DSM812. Multi-link logical entity allows STAs814,816within the multi-link logical entity to have the same MAC address, in accordance with some embodiments. In some embodiments a same MAC address is used for application layers and a different MAC address is used per link802.

In infrastructure framework, AP MLD808, includes APs830,832,834, on one side, and non-AP MLD 3809includes non-APs STAs818,820,822on the other side. AP MLD808is a ML logical entity, where each STA within the multi-link logical entity is an EHT AP502, in accordance with some embodiments. Non-AP MLD 1806, non-AP MLD 2807, non-AP MLD809are multi-link logical entities, where each STA within the multi-link logical entity is a non-AP EHT STA504. AP1830, AP2832, and AP3834may be operating on different bands and there may be fewer or more APs. STA1.1814.1, STA1.2814.2, and STA1.3814.3may be operating on different bands and there may be fewer or more STAs as part of the non-AP MLD 3809.

In some embodiments, a multi-link device (MLD),806or807, is a device that is a logical entity and has more than one affiliated station (STA), e.g., STAs814, and has a single medium access control (MAC) service access point (SAP) to logical link control (LLC), which includes one MAC data service.

In some embodiments, a physical layer protocol data unit may be a physical layer conformance procedure (PLCP) protocol data unit (PPDU). In some embodiments, the AP and STAs may communicate in accordance with one of the IEEE 802.11 standards. IEEE Std 802.11-2020 is incorporated herein by reference. IEEE P802.11-REVmd/D2.4, August 2019, and IEEE draft specification IEEE P802.11ax/D5.0, October 2019 are incorporated herein by reference in their entireties. In some embodiments, the AP and STAs may be directional multi-gigabit (DMG) STAs or enhanced DMG (EDMG) STAs configured to communicate in accordance with IEEE 802.11ad standard or IEEE draft specification IEEE P802.11ay, February 2019, which is incorporated herein by reference.

Sensing is the use of PHY and MAC features of IEEE 802.11 stations to obtain measurements that may be useful to estimate features such as range, velocity, and motion of objects in an area of interest. Measurements obtained with WLAN sensing may be used to enable applications such as presence detection and gesture classification. IEEE 802.11bf is a draft standard that aims to standardize WLAN sensing that uses Wi-Fi technology to perform radar-like applications such as detecting motion in a room or detecting when a person approaches a target device. IEEE P802.11bf/D0.4, November 2022 is incorporated herein by reference. Sensing is performed by tracking channel estimates obtained when decoding multiple Wi-Fi packets over time and detecting variations that indicate an event of interest

Threshold-based reporting is optional and may be present in a TB sensing measurement instance in which the sensing responder is in the role of sensing receiver. Threshold-based reporting phase consists of a CSI variation reporting sub-phase and may additionally include a measurement reporting sub-phase. Only sensing responders that report their CSI variation value greater than or equal to the CSI variation threshold assigned to them participate in the measurement reporting sub-phase. CSI variation indicates the quantified difference between the current measured CSI and the previous measured CSI at a sensing responder. The CSI variation threshold for each sensing responder to be compared with the CSI variation value is determined by the sensing initiator, and is transmitted to each sensing responder within a TBD frame. Different sensing responders may have different threshold values set by the sensing initiator.

If the non-AP STA is only the sensing transmitter, the Sensing NDP Announcement frame should configure the SR2SI NDP to be transmitted with the minimum possible length of one LTF symbol. If the non-AP STA is only the sensing receiver, the Sensing NDP Announcement frame should configure the SI2SR NDP to be transmitted with the minimum possible length of one LTF symbol.

In the polling phase, the AP polls five STAs, where STA1 and STA2 are sensing transmitters and STA3, STA4, and STA5 are sensing receivers. STA1-STA4 respond to the AP with CTS-to-self, so both TF sounding phase and NDPA sounding phase are present. In the TF sounding phase, the AP sends a Sensing Sounding Trigger frame to STA1 and STA2 to solicit sensing responder to sensing initiator (SR2SI) NDP transmissions. In the NDPA sounding phase, the AP sends a Sensing NDP Announcement frame followed by SI2SR NDP to STA3 and STA4.

SBP is a procedure that allows a non-AP STA to request an AP to perform WLAN sensing on its behalf. To establish an SBP procedure, the SBP initiator shall send an SBP Request frame to an SBP responder. Upon receipt of an SBP Request frame, the SBP responder either accepts the SBP procedure request, in which case the SBP responder shall send an SBP Response frame with Status Code field set to SUCCESS; or rejects the SBP procedure request, in which case the SBP responder shall send an SBP Response frame with Status Code field set to REQUEST DECLINED.

The SBP initiator shall include one Availability Window element in the SBP request frame indicating its availability for SBP reporting and for TB sensing measurement instance if the SBP initiator intends to be a sensing responder. The periodicity of the availability windows requested by the SBP initiator is expressed in units of 10 TUs in the Count subfield in the ISTA Availability Information field of the ISTA Availability Window element. The value of the Count subfield in the ISTA Availability Information field of the ISTA Availability Window element shall be a multiple of the Beacon Interval of the SBP responder in units of 10 TUs. The requested sensing measurement periodicity is the same as the requested periodicity of the availability windows.

In some embodiments, an AP may be configured to perform a WLAN sensing procedure. In these embodiments, the AP may encode a Sensing Sounding Trigger Frame for transmission to one or more of the STAs that are operating as sensing transmitters to solicit sensing packet transmissions. The AP may decode the sensing packet transmissions received from the one or more of the STAs that are operating as sensing transmitters. The AP may encode a Sensing Packet Announcement Frame for transmission followed by a sensing packet to one or more of the STAs that are operating as sensing receivers. The AP may also perform sensing measurements on the sensing packet transmissions received from the one or more of the STAs that are operating as sensing transmitters. During a reporting phase, the AP may be configured to encode a Sensing Report Trigger Frame for transmission to the one or more STAs that are operating as sensing receivers and decode a Sensing Measurement Report Frame sent by the one or more STAs that are operating as sensing receivers in response to the Sensing Report Trigger Frame, the Sensing Measurement Report Frame containing sensing measurement results.

In some embodiments, the channel measurements comprise measurements of channel variation based on channel state information (CSI), and the sensing measurements may be performed in accordance with a sensing measurement agreement. In some embodiments, the channel measurements may be based on long-training fields (LTFs) of sensing measurement packets. In these embodiments, the AP may estimate features such as range, velocity, and motion of objects in an area of interest based on the sensing measurements to enable applications such as presence detection and gesture classification. The AP may also determine channel state information (CSI) variation from the sensing measurements and the sensing measurement results for use in estimating motion of an object in an area of interest. In some embodiments, the sensing measurements may be performed in accordance with a measurement periodicity. In some embodiments, the CSI variation may be determined for each of a plurality of links with the AP and the AP may be configured to track the CSI variation for each of a plurality of links.

In a trigger-based (TB) sensing measurement scheme, a STA negotiates periodic time windows with an AP in which they perform sensing measurements through exchange of Control frames and NDP PPDUs. Due to clock drift the location of these time-windows may drift if the STA does not keep track of the AP's time synchronization function (TSF). While the TSF information may be included in the beacon an unassociated STA may not be able to track this efficiently. For example, since the STA may need to go off-channel to perform sensing with this AP, tracking beacons would require the STA to go off-channel again more frequently thereby affecting its data connectivity and power save behavior. Embodiments disclosed herein address the issue of how a STA efficiently tracks the TSF information of the AP its performing TB sensing measurements with.

The 11az TB ranging measurement sequence experiences a similar problem and addresses this in the following way:

The AP records the TSF time when it sent a TF Ranging Poll in the measurement instance.Later, in the same measurement instance when it sends a Ranging NDP Announcement frame, it also includes the Partial TSF time of the above recorded TSF inside a STA Info field with special AID11 value of 2044.A STA corrects the received TSF info after comparing its own TSF at the time when the TF Poll was received with the Partial TSF value obtained in the NDP-A.

This 11az mechanism does not work for the case when there is no NDP-A sounding phase.

FIG.9illustrates an Example of Special User Info field containing a partial TSF information, in accordance with some embodiments. In the various embodiments disclosed herein, the Sensing Sounding Trigger frame and the Sensing R2R Sounding Trigger frame may be encoded to include a Special User Info field that carries the partial TSF of the time when the Sensing Poll Trigger frame was sent. In some embodiments the Special User Info field containing the partial TSF information may have the following format: shown inFIG.9.

In some embodiments, AID12: a special AID value (e.g., 2008 or 2006) not assigned to any other STA by this AP.

In some embodiments, Partial TSF: a partial value for the TSF (e.g., the bits [21:6]) when a preceding frame (e.g., Sensing Poll Trigger frame) was sent in the same measurement instance.

In some embodiments, Token: the value of the Token field in the previous Sensing Poll Trigger frame.

FIG.10illustrates an example of using a sensing sounding trigger frame to synchronize the TSF at an unassociated STA performing TB sensing, in accordance with some embodiments.

In some embodiments the Special User Info field may be absent if there is an NDP-A Sounding phase in which case a special STA Info field in the NDP-A (e.g., a STA Info field with AID11 value set to 2044) may contain the partial TSF information of the preceding Sensing Poll Trigger frame.FIG.10illustrates an example of such a signaling within a single TB sensing measurement instance.

In some embodiments the Special User Info field may be present only in the first Sensing Sounding Trigger or Sensing R2R Sounding Trigger frame.

In some embodiments the Special User Info field may be present only in the first Sensing Sounding Trigger or Sensing R2R Sounding Trigger frame for which the AP received a response PPDU.

The STA that receives the Partial TSF Information may follow the same rules as the one described in 11az draft 7.0 to compare the received Partial TSF Information with its own TSF when the Sensing Poll Trigger frame was received and then synchronize its TSF time to determine start of next Sensing availability window, although the scope of the embodiments is not limited in this respect.

In some embodiments, when transmitting a Sensing NDP Announcement frame as part of a TB sensing measurement instance, an AP shall include a value in the Partial TSF subfield in the STA Info field with the AID11 subfield equal to 2044, that equals to the AP's TSF[21:6] at the time of transmission of the preceding Sensing Poll Trigger frame. Specifically, the time that the first data symbol of the PSDU of the frame was transmitted to the PHY plus the AP's delays through its local PHY from the MAC-PHY interface to its interface with the WM. Additionally, the AP shall set the Token subfield in the STA Info field with the AID11 subfield equal to 2044 in the Sensing NDP Announcement frame to the same trigger poll counter value as the Token subfield in the Sensing Poll Trigger frame whose partial TSF time is carried in the Sensing NDP Announcement frame.

In some embodiments, when transmitting a Sensing Sounding Trigger frame as part of a TB sensing measurement instance, an AP shall include a value in the Partial TSF subfield in the User Info field with the AID12/USID12 subfield equal to 2008, that equals to the AP's TSF[21:6] at the time of transmission of the preceding Sensing Poll Trigger frame in that measurement instance. Specifically, the time that the first data symbol of the PSDU of the frame was transmitted to the PHY plus the AP's delays through its local PHY from the MAC-PHY interface to its interface with the WM. Additionally, the AP shall set the Token subfield in the User Info field with the AID12/USID12 subfield equal to 2008 in the Sensing Sounding Trigger frame to the same trigger poll counter value as the Token subfield in the Sensing Poll Trigger frame whose partial TSF time is carried in the Sensing Sounding Trigger frame.

In some embodiments, when transmitting an SR2SR Sounding Trigger frame as part of the TB sensing measurement instance, an AP shall include a value in the Partial TSF subfield in the User Info field with the AID12/USID12 subfield equal to 2008 that equals to the AP's TSF[21:6] at the time of transmission of the preceding Sensing Poll Trigger frame in that measurement instance. Specifically, the time that the first data symbol of the PSDU of said frame was transmitted to the PHY plus the AP's delays through its local PHY from the MAC-PHY interface to its interface with the WM. Additionally, the AP shall set the Token subfield in the User Info field with the AID12/USID12 subfield equal to 2008 in the SR2SR Sounding Trigger frame to the same trigger poll counter value as the Token subfield in the Sensing Poll Trigger frame whose partial TSF time is carried in the SR2SR Sounding Trigger frame.

Some embodiments are directed to a non-access point station (STA) configured for performing wireless local area network (WLAN) sensing. In these embodiments, for performing the WLAN sensing, the STA is configured to decode a sensing poll trigger frame (TF)1002(FIG.10) received from an access point station (AP) during a polling phase of a trigger-based (TB) sensing measurement instance. In these embodiments, the sending poll TF may be configured to poll one or more non-AP STAs including the STA. The STA may also encode a CTS-to-self frame1004for transmission to the AP in response to the sensing poll TF1002during the polling phase of the TB sensing measurement instance.

In these embodiments, the STA may also decode a sensing sounding TF1006received from the AP during a TF sounding phase of the TB sensing measurement instance. The STA may also encode a sensing responder to sensing initiator (SR2SI) null-data packet (NDP) for transmission to the AP in response to the sensing sounding TF1006during the TF sounding phase of the TB sensing measurement instance.

In these embodiments, when the sensing poll TF1002and the sensing sounding TF1006are received in a same sensing measurement instance and when the sensing sounding TF1006includes a special user information field900(FIG.9) containing partial time-synchronization function (TSF) information904, the STA may be configured to update a TSF of the STA based on the partial TSF information. These embodiments allow an unassociated STA to efficiently track the TSF information of the AP for performing TB sensing measurements.

In some embodiments, the STA may be configured to determine a start time of a next sensing availability window using the updated (i.e., synchronized) TSF of the STA. In these embodiments, the next sensing availability window is one of a plurality of periodically occurring sensing availability windows that occur based on a periodicity (e.g., requested by a sensing-by-proxy (SBP) initiator).

In some embodiments, the special user information field900includes a token906. In these embodiments, the STA may determine that the sensing poll TF1002and the sensing sounding TF1006are received in the same sensing measurement instance when the token906in the special user information field900matches (i.e., is the same as) a token received in the sensing poll TF1002.

In some embodiments, the partial TSF contained in the special user information field of the sensing sounding TF may comprise a partial value for a TSF of the AP at a time when the sensing poll TF was sent by the AP (i.e., the value of the time at which the preceding Sensing Poll TF was sent). In these embodiments, STA may synchronize its TSF with a TSF of the AP based on a comparison of the partial TSF information with a TSF of the STA at a time (e.g., T1—seeFIG.10) when the sensing poll TF1002was received. In these embodiments, the STA may also determine the start time of next sensing availability window based on the synchronized TSF of the STA. In these embodiments, the partial TSF is a partial value for the TSF when a preceding frame (e.g., the sensing poll TF) was sent in the same measurement instance. In these embodiments, the sensing poll TF did not include TSF information.

In some embodiments, when the sensing poll TF1002contains TSF information of the AP and when the sensing poll TF1002and the sensing sounding TF1006are received in the same sensing measurement instance, the STA may be configured to update the TSF of the STA based on the TSF information received in the sensing poll TF1002.

In some embodiments, when the STA is unassociated with the AP, the STA may update the TSF of the STA based on the partial TSF information received in the sensing sounding TF1006. In these embodiments, when the STA is associated with the AP, the STA may update the TSF based on receipt of beacon frames received from the AP. The beacon frames may include the TSF of the AP. In these embodiments, an associated STA may not need to update its TSF since TSF information was received in beacon frames. In these embodiments, as associated STA may refrain from updating its TSF the STA based partial TSF information that may be contained in the sensing sounding TF1006.

In some embodiments, when the special user information field900includes one or more predetermined association ID (AID) values902, the STA may determine that the special user information field900contains the partial TSF information904. In these embodiments, the one or more predetermined AID values (i.e., special AIDs) (e.g., 2008 or 2006) are AID values that are not assigned to any STA by the AP.

In some embodiments, the User Info field of an for SR2SI Sounding Trigger frame, if the AID12/USID12 subfield is equal to 2008, may be used to carry the Partial TSF subfield. The Partial TSF subfield may contain 16 bits of the AP's TSF time, TSF21:6, when the AP transmitted the Sensing Poll Trigger frame that preceded the Sensing Sounding Trigger frame carrying this User Info field. In these embodiments, the Token subfield may be set to the value of the Token subfield of the Sensing Poll Trigger frame whose partial transmission TSF time is carried. The Trigger Dependent User Info subfield may not be present in the SR2SI Sounding Trigger frame.

In some embodiments, when the special user information field900does not include the one or more predetermined association ID (AID) values902, the STA may determine that the special user information field900does not contain the partial TSF information904and may refrain from updating the TSF of the STA.

In some embodiments, the sensing sounding TF1006may be a first sensing sounding TF in the sensing measurement instance. When the first sensing sounding TF includes the special user information field with the partial TSF information, any subsequent sensing sounding TFs received in the same sensing measurement instance may be received without a special user information field. In these embodiments, the Special User Info field may be present only in the first Sensing Sounding Trigger or Sensing R2R Sounding Trigger frame. In some embodiments, the Special User Info field may be present only in the first Sensing Sounding Trigger or Sensing R2R Sounding Trigger frame for which the AP received a response PPDU.

In some embodiments, during an NDP-A sounding phase, the STA may be configured to decode an NDP-A received from the AP to determine partial TSF information of a preceding sensing poll TF (e.g., sensing poll TF1002(FIG.10)). In these embodiments, the NDP-A may include a special STA information field with a predetermine AID value (e.g., a STA Info field with AID11 value set to 2044). In these embodiments, the STA Info field with AID11 subfield equal to 2044 may be used in TB sensing measurement instances to carry the Partial TSF subfield. The Partial TSF subfield may contain 16 bits of the AP's TSF time, TSF 21:6, if the AP that transmitted the Sensing Poll Trigger frame that preceded the Sensing NDP Announcement frame carrying this STA Info field with AID subfield is equal to 2044. In these embodiments, the Token subfield may be set to the value of the Token subfield of the Sensing Poll Trigger frame whose partial transmission TSF time is carried. In some embodiments, the Token field in the Trigger Dependent Common Info subfield is used in a Sensing Poll Trigger frame to match it with the partial TSF time in a following Sensing NDP Announcement frame or a Sensing Sounding Trigger frame.

In some embodiments, in response to the sensing sounding TF1006, the STA may perform sensing measurements with the AP. In these embodiments, the sensing measurements may include channel measurements of a channel between the STA and the AP. In these embodiments, the STA may receive sensing measurement results from the AP that include sensing measurements performed between the AP and one or more other STAs. In these embodiments, the STA may also estimate features of objects, other than the STA and the AP, in an area of interest based on the channel measurements.

In some embodiments, the channel measurements may comprise measurements of channel variation based on channel state information (CSI). In these embodiments, the sensing measurements may be performed in accordance with a sensing measurement agreement. In some of these embodiments, the channel measurements may be based on long-training fields (LTFs) of sensing measurement packets. In these embodiments, the STA may be further configured to estimate features such as range, velocity, and motion of objects in an area of interest based on the sensing measurements to enable applications such as presence detection and gesture classification.

Some embodiments are directed to a non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a non-access point station (STA). To configure the STA for performing wireless local area network (WLAN) sensing, the processing circuitry may be configured to update a TSF of the STA based on partial TSF information when the sensing poll TF1002and the sensing sounding TF1006are received in a same sensing measurement instance and when the sensing sounding TF1006includes a special user information field900(FIG.9) containing the partial TSF information904.

Some embodiments are directed to access point station (AP) configured for performing wireless local area network (WLAN) sensing. In these embodiments, the AP may be configured to encode a sensing poll trigger frame (TF)1002(FIG.10) for transmission to a non-AP station (STA). The sending poll TF may be configured to poll one or more non-AP STAs during a polling phase of a trigger-based (TB) sensing measurement instance. The AP may also decode a CTS-to-self frame1004received from the STA in response to the sensing poll TF1002. The AP may also encode a sensing sounding TF1006for transmission to the STA during a TF sounding phase of the TB sensing measurement instance. The AP may also be configured to decode a sensing responder to sensing initiator (SR2SI) null-data packet (NDP) received from the STA in response to the sensing sounding TF1006during the TF sounding phase of the TB sensing measurement instance. In these embodiments, when the sensing poll TF1002and the sensing sounding TF1006are transmitted in a same sensing measurement instance, the AP may be configured to include a special user information field900(FIG.9) containing partial time-synchronization function (TSF) information904in the sensing sounding TF1006for use by the STA to update a TSF of the STA.

In some embodiments, when the AP may include a same token in the special user information field to indicate that the sensing poll TF1002and the sensing sounding TF1006are transmitted in the same sensing measurement instance.

FIG.11illustrates a procedure1100for updating a TSF of an unassociated non-AP STA for WLAN sensing, in accordance with some embodiments.

In operation1102, the non-AP STA may decode a sensing poll trigger frame (TF)1002(FIG.10) received from an access point station (AP) during a polling phase of a trigger-based (TB) sensing measurement instance. The sending poll TF may be configured to poll one or more non-AP STAs including the STA.

In operation1104, the STA may encode a CTS-to-self frame1004for transmission to the AP in response to the sensing poll TF1002during the polling phase.

In operation1106, the STA may decode a sensing sounding TF1006received from the AP during a TF sounding phase of the TB sensing measurement instance.

In operation1108, the STA may encode a sensing responder to sensing initiator (SR2SI) null-data packet (NDP) for transmission to the AP in response to the sensing sounding TF1006during a TF sounding phase of the TB sensing measurement instance.

In operation1110, wherein when the sensing poll TF1002and the sensing sounding TF1006are received in a same sensing measurement instance and when the sensing sounding TF1006includes a special user information field900(FIG.9) containing partial time-synchronization function (TSF) information904, the STA may update a TSF of the STA based on the partial TSF information.