Systems and methods to form a sensing network

Abstract

Systems and methods are disclosed to form a sensing network carried out by a networking device. Methods are provided to form the sensing network. The method may be carried out by a networking device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions. The method includes receiving, from an associated AP, client device information associated with a plurality of client devices in an extended service set. Further, the method includes selecting a PACD from among the plurality of client devices according to the client device information. The method further includes selecting a common frequency channel according to a frequency channel in use by the PACD. The method also includes sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel.

Description

SYSTEMS AND METHODS TO FORM A SENSING NETWORK TECHNICAL FIELD

[0001] The present disclosure generally relates to systems and methods for wireless local 5 area (WLAN) sensing. In particular, the present disclosure relates to systems and methods to form a sensing network. BACKGROUND OF THE DISCLOSURE

[0002] Motion detection systems have been used to detect movement, for example, of 10 objects in a room or an outdoor area. In some example motion detection systems, infrared or optical sensors are used to detect movement of objects in the sensor’s field of view. Motion detection systems have been used in security systems, automated control systems, and other types of systems. A Wireless Local Area Network (WLAN) sensing system (which may be referred to as a Wireless Fidelity (Wi-Fi) sensing system) is one recent addition to motion 15 detection systems. The Wi-Fi sensing system may be a network of Wi-Fi-enabled devices that may be a part of an Institute of Electrical and Electronics Engineers (IEEE) 802.11 network (sometimes referred to as a Basic Service Set, BSS, or Extended Service Set, ESS). In an example, a Wi-Fi sensing system may be configured to detect features of interest in a sensing space. A sensing space may refer to any physical space in which the Wi-Fi sensing system may 20 operate, such as a place of residence, a place of work, a shopping mall, a sports hall or sports stadium, a garden, or any other physical space. Features of interest may include motion of objects and motion tracking, presence detection, intrusion detection, gesture recognition, fall detection, breathing rate detection, and other applications.

[0003] Further, the motion is determined in the sensing space by a sensing 25 algorithm / technique on a device detecting perturbation in the local environment based on analysis of sensing measurements (channel state information) over time. Further, a sensing transmission is sent from a sensing transmitter. Furthermore, a sensing receiver performs a sensing measurement at the Physical (PHY) / Media Access Control layer (MAC) layer and passes this up to a sensing agent or sensing algorithm at a higher layer to detect motion. 30

[0004] Furthermore, the BSS is set of an Access Point Station (AP STA) and non-AP STAs associated together at the PHY / MAC layer to form a wireless network. The BSS comprises of a single device acting as an access point (AP or AP STA) and one or more devices connectedto and controlled by the AP (non-AP STA, or simply STA where the access point is AP). A BSS is identified in IEEE 802.11 by a BSSID. Further, the ESS is a group of two or more BSSs interconnected by a network (such as a wired network). The ESS allows client devices to roam between different BSSs while maintaining connectivity to the network. 5 BRIEF SUMMARY OF THE DISCLOSURE

[0005] The present disclosure generally relates to systems and methods for establishing a Wi-Fi sensing network. In particular, the present disclosure relates to systems and methods for establishing a Wi-Fi sensing network carried out by a client device.

[0006] Methods are provided to form a sensing network. In an example embodiment, a 10 method to form a sensing network is described. The method may be carried out by a client device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions. The method includes receiving, from an associated access point (AP), client device information associated with a plurality of client devices in an extended service set. Further, the method includes selecting a proxy AP client device (PACD) from 15 among the plurality of client devices according to the client device information, with the PACD being associated with a current selected AP. The method further includes selecting a common frequency channel according to a frequency channel in use by the PACD. The method also includes sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel. 20

[0007] In some embodiments, the method includes transmitting, to the associated AP, a sensing pulse packet including at least a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device. In an example, the client device information associated with each specific client device of the plurality of client devices includes at least PACD capability of the specific client device, a frequency channel 25 associated with the AP in association with the specific client device, and a current PACD status of the specific client device.

[0008] In some embodiments, selecting the PACD includes identifying the current selected AP as having the largest number of associated client devices from the plurality of client devices. Further, the method includes identifying PACD capable devices associated with 30 the current selected AP. The method also includes selecting, as the PACD, the PACD capable device having a data frame signal to noise ratio (SNR) in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP.

[0009] In some embodiments, the common frequency channel is a channel in use between the PACD and the current selected AP associated with the PACD.

[0010] In some embodiments, the method includes entering a sleep mode with respect to the current selected AP to perform sensing. Further, the method includes exiting the sleep mode 5 to perform data transmissions with the current selected AP.

[0011] In some embodiments, entering the sleep mode is initiated responsive to receipt of a data message.

[0012] In some embodiments, entering the sleep mode is initiated according to predetermined timing. 10

[0013] In some embodiments, the plurality of client devices includes the client device, and the client device is selected as the PACD.

[0014] In some embodiments, the method includes initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices. Further, the method includes receiving a sensing transmission from the one of the plurality of client devices. 15

[0015] In some embodiments, the method includes initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices. Further, the method includes receiving a sensing measurement report from the one of the plurality of client devices.

[0016] In some embodiments, the method includes initiating, by the client device, a 20 sensing session between two of the plurality of client devices. Further, the method includes receiving a sensing measurement report from the one of the two of the plurality of client devices.

[0017] In some embodiments, the plurality of client devices includes the client device, and the client device is not selected as the PACD. 25

[0018] In some embodiments, the method includes receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with the PACD. Further, the method includes transmitting, to the PACD, a sensing measurement report or a sensing transmission.

[0019] In some embodiments, the method includes receiving, from the PACD, a sensing 30 trigger message to initiate a trigger based sensing measurement exchange with one client device from the plurality of client devices.

[0020] In some embodiments, the method includes if the client device is not associated with the current selected AP, responsive to a beacon signal to noise ratio between the clientdevice and the current selected AP surpassing a threshold, associating with the current selected AP. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG.1 is a diagram showing an example wireless communication system. 5

[0022] FIG. 2A and FIG. 2B are diagrams showing example wireless signals communicated between wireless communication devices.

[0023] FIG.3A and FIG.3B are plots showing examples of channel responses computed from the wireless signals communicated between wireless communication devices in FIG.2A and FIG.2B. 10

[0024] FIG.4A and FIG.4B are diagrams showing example channel responses associated with motion of an object in distinct regions of a space.

[0025] FIG.4C and FIG.4D are plots showing the example channel responses of FIG.4A and FIG.4B overlaid on an example channel response associated with no motion occurring in the space. 15

[0026] FIG. 5 depicts an implementation of some of an architecture of a system for establishing a Wi-Fi sensing network, according to some embodiments.

[0027] FIG. 6 depicts an example of a WLAN sensing procedure, according to some embodiments.

[0028] FIG. 7A depicts an example of a Sensing Measurement Setup Request frame 20 Action field format, according to some embodiments.

[0029] FIG.7B illustrates an example of a Sensing Measurement Parameters element, according to some embodiments.

[0030] FIG.7C illustrates an example of a format of a Sensing Measurement Parameters field, according to some embodiments. 25

[0031] FIG.7D depicts an example of a Sensing Measurement Setup Response frame Action field format, according to some embodiments.

[0032] FIG.8A depicts one-to-many and many-to-one aspects of an example of a WLAN sensing procedure, according to some embodiments.

[0033] FIG.8B depicts pairwise aspects of an example of a WLAN sensing procedure, 30 according to some embodiments.

[0034] FIG.9A and FIG.9B depict an example of message flows of a trigger-based (TB) sensing measurement exchange of a WLAN sensing procedure that consists of a sensingmeasurement setup phase, an NDPA sounding and reporting phase, a TF sounding phase, and a sensing measurement setup termination phase, according to some embodiments.

[0035] FIG.10A depicts an example of phases of a TB sensing measurement exchange, according to some embodiments. 5

[0036] FIG.10B indicates valid combinations of phases of a TB sensing measurement exchange, according to some embodiments.

[0037] FIG.11 depicts an example of a TB sensing measurement exchange including a polling phase, an NDPA sounding phase, a TF sounding phase and a reporting phase, according to some embodiments. 10

[0038] FIG.12A and FIG.12B depicts a message flow of a non-TB sensing measurement exchange of a WLAN sensing procedure that consists of a sensing measurement setup phase, an NDPA sounding phase with sensing initiator to sensing responder (SI2SR) sounding and reporting, an NDPA sounding phase with sensing responder to sensing initiator (SR2SI) sounding, an NDPA sounding phase with both SI2SR sounding and reporting and SR2SI 15 sounding, and a sensing measurement setup termination phase, according to some embodiments.

[0039] FIG.13 depicts an example of a single non-TB sensing measurement exchange consisting of a measurement sounding phase and a reporting phase, according to some embodiments. 20

[0040] FIG.14A and FIG.14B depict an example of an Action field format of a Sensing Measurement Report frame Action field and a Sensing Measurement Report Container field format, according to some embodiments.

[0041] FIG.15A to FIG.15I depict a hierarchy of fields within a Sensing Trigger frame, according to some embodiments. 25

[0042] FIG. 16 depicts an exemplary Extended Service Set (ESS), according to some embodiments.

[0043] FIG. 17 depicts an exemplary WLAN networking showing sensing links on a common frequency channel, according to some embodiments.

[0044] FIG.18 depicts an exemplary flowchart for establishing a Wi-Fi sensing network 30 carried out by a client device, according to some embodiments.

[0045] FIG.19 depicts an exemplary flowchart for selecting the PACD, according to some embodiments.

[0046] FIG.20 to FIG.22 depict exemplary flowcharts for entering and exiting the sleep mode carried out by a client device as a sensing initiator, according to some embodiments.

[0047] FIG.23 depicts an exemplary flowchart for establishing the Wi-Fi sensing network carried out by a client device as a sensing responder, according to some embodiments. DETAILED DESCRIPTION

[0048] Wireless sensing enables a device to obtain sensing measurements of transmission 5 channel(s) between two or more devices. With the execution of a wireless sensing procedure, it is possible for a device to obtain sensing measurements useful for detecting and tracking changes in the environment. In some aspects of what is described herein, a wireless sensing system may be used for a variety of wireless sensing applications by processing wireless signals (e.g., radio frequency (RF) signals) transmitted through a space between wireless 10 communication devices. Example wireless sensing applications include motion detection, which can include the following: detecting motion of objects in the space, motion tracking, breathing detection, breathing monitoring, presence detection, gesture detection, gesture recognition, human detection (moving and stationary human detection), human tracking, fall detection, speed estimation, intrusion detection, walking detection, step counting, respiration 15 rate detection, apnea estimation, posture change detection, activity recognition, gait rate classification, gesture decoding, sign language recognition, hand tracking, heart rate estimation, breathing rate estimation, room occupancy detection, human dynamics monitoring, and other types of motion detection applications. Other examples of wireless sensing applications include object recognition, speaking recognition, keystroke detection and 20 recognition, tamper detection, touch detection, attack detection, user authentication, driver fatigue detection, traffic monitoring, smoking detection, school safety issue detection, human counting, human recognition, bike localization, human queue estimation, Wi-Fi imaging, and other types of wireless sensing applications. For instance, the wireless sensing system may operate as a motion detection system to detect the existence and location of motion based on 25 Wi-Fi signals or other types of wireless signals. As described in more detail below, a wireless sensing system may be configured to control measurement rates, wireless connections, and device participation, for example, to improve system operation or to achieve other technical advantages. The system improvements and technical advantages achieved when the wireless sensing system is used for motion detection are also achieved in examples where the wireless 30 sensing system is used for another type of wireless sensing application.

[0049] In some example wireless sensing systems, a wireless signal includes a component (e.g., a synchronization preamble in a Wi-Fi PHY frame, or another type of component) that wireless devices can use to estimate a channel response or other channel information, and thewireless sensing system can detect motion (or another characteristic depending on the wireless sensing application) by analyzing changes in the channel information collected over time. In some examples, a wireless sensing system can operate similar to a bistatic radar system, where a Wi-Fi access point (AP) assumes the receiver role, and each Wi-Fi device (station (STA), 5 node, or peer) connected to the AP assumes the transmitter role. The wireless sensing system may trigger a connected device to generate a transmission and produce a channel response measurement at a receiver device. This triggering process can be repeated periodically to obtain a sequence of time variant measurements. A wireless sensing algorithm may then receive the generated time-series of channel response measurements (e.g., computed by Wi-Fi receivers) 10 as input, and through a correlation or filtering process, may then make a determination (e.g., determine if there is motion or no motion within the environment represented by the channel response, for example, based on changes or patterns in the channel estimations). In examples where the wireless sensing system detects motion, it may also be possible to identify a location of the motion within the environment based on motion detection results among a number of 15 wireless devices.

[0050] Accordingly, wireless signals received at each of the wireless communication devices in a wireless communication network may be analyzed to determine channel information for the various communication links (between respective pairs of wireless communication devices) in the network. The channel information may be representative of a 20 physical medium that applies a transfer function to wireless signals that traverse a space. In some instances, the channel information includes a channel response. Channel responses can characterize a physical communication path, representing the combined effect of, for example, scattering, fading, and power decay within the space between the transmitter and receiver. In some instances, the channel information includes beamforming state information (e.g., a 25 feedback matrix, a steering matrix, channel state information, etc.) provided by a beamforming system. Beamforming is a signal processing technique often used in multi antenna (multiple- input / multiple-output (MIMO)) radio systems for directional signal transmission or reception. Beamforming can be achieved by operating elements in an antenna array in such a way that signals at some angles experience constructive interference while others experience destructive 30 interference.

[0051] The channel information for each of the communication links may be analyzed (e.g., by a hub device or other device in a wireless communication network, or a sensing transmitter, sensing receiver, or sensing initiator communicably coupled to the network) to, for example, detect whether motion has occurred in the space, to determine a relative location ofthe detected motion, or both. In some aspects, the channel information for each of the communication links may be analyzed to detect whether an object is present or absent, e.g., when no motion is detected in the space.

[0052] In some cases, a wireless sensing system can control a node measurement rate. For 5 instance, a Wi-Fi motion system may configure variable measurement rates (e.g., channel estimation / environment measurement / sampling rates) based on criteria given by a current wireless sensing application (e.g., motion detection). In some implementations, when no motion is present or no motion is detected for a period of time, for example, the wireless sensing system can reduce the rate that the environment is measured, such that the connected device 10 will be triggered or caused to make sensing transmissions or sensing measurements less frequently. In some implementations, when motion is present, for example, the wireless sensing system can increase the triggering rate or sensing transmissions rate or sensing measurement rate to produce a time-series of measurements with finer time resolution. Controlling a variable sensing measurement rate can allow energy conservation (through the device triggering), 15 reduce processing (less data to correlate or filter), and improve resolution during specified times.

[0053] In some cases, a wireless sensing system can perform band steering or client steering of nodes throughout a wireless network, for example, in a Wi-Fi multi-AP or extended service set (ESS) topology, multiple coordinating wireless APs each provide a basic service set 20 (BSS) which may occupy different frequency bands and allow devices to transparently move between one participating AP and another (e.g., mesh). For instance, within a home mesh network, Wi-Fi devices can connect to any of the APs, but typically select one with good signal strength. The coverage footprint of the mesh APs typically overlaps, often putting each device within communication range or more than one AP. If the AP supports multi-bands (e.g., 25 2.4 GHz and 5 GHz), the wireless sensing system may keep a device connected to the same physical AP but instruct it to use a different frequency band to obtain more diverse information to help improve the accuracy or results of the wireless sensing algorithm (e.g., motion detection algorithm). In some implementations, the wireless sensing system can change a device from being connected to one mesh AP to being connected to another mesh AP. Such device steering 30 can be performed, for example, during wireless sensing (e.g., motion detection), based on criteria detected in a specific area to improve detection coverage, or to better localize motion within an area.

[0054] In some cases, beamforming may be performed between wireless communication devices based on some knowledge of the communication channel (e.g., through feedbackproperties generated by a receiver), which can be used to generate one or more steering properties (e.g., a steering matrix) that are applied by a transmitter device to shape the transmitted beam / signal in a particular direction or directions. Thus, changes to the steering or feedback properties used in the beamforming process indicate changes, which may be caused 5 by moving objects, in the space accessed by the wireless communication system. For example, motion may be detected by substantial changes in the communication channel, e.g., as indicated by a channel response, or steering or feedback properties, or any combination thereof, over a period of time.

[0055] In some implementations, for example, a steering matrix may be generated at a 10 transmitter device (beamformer) based on a feedback matrix provided by a receiver device (beamformee) based on channel sounding. Because the steering and feedback matrices are related to propagation characteristics of the channel, these matrices change as objects move within the channel. Changes in the channel characteristics are accordingly reflected in these matrices, and by analyzing the matrices, motion can be detected, and different characteristics 15 of the detected motion can be determined. In some implementations, a spatial map may be generated based on one or more beamforming matrices. The spatial map may indicate a general direction of an object in a space relative to a wireless communication device. In some cases, many beamforming matrices (e.g., feedback matrices or steering matrices) may be generated to represent a multitude of directions that an object may be located relative to a wireless 20 communication device. These many beamforming matrices may be used to generate the spatial map. The spatial map may be used to detect the presence of motion in the space or to detect a location of the detected motion.

[0056] In some instances, a motion detection system can control a variable device measurement rate in a motion detection process. For example, a feedback control system for a 25 multi-node wireless motion detection system may adaptively change the sample rate based on environmental conditions. In some cases, such controls can improve operation of the motion detection system or provide other technical advantages. For example, the measurement rate may be controlled in a manner that optimizes or otherwise improves air-time usage versus detection ability suitable for a wide range of different environments and different motion 30 detection applications. The measurement rate may be controlled in a manner that reduces redundant measurement data to be processed, thereby reducing processor load / power requirements. In some cases, the measurement rate is controlled in a manner that is adaptive, for instance, an adaptive sample can be controlled individually for each participating device.An adaptive sample rate can be used with a tuning control loop for different use cases, or device characteristics.

[0057] In some cases, a wireless sensing system can allow devices to dynamically indicate and communicate their wireless sensing capability or wireless sensing willingness to the 5 wireless sensing system. For example, there may be times when a device does not want to be periodically interrupted or triggered to transmit a wireless signal that would allow the AP to produce a channel measurement. For instance, if a device is sleeping, frequently waking the device up to transmit or receive wireless sensing signals could consume resources (e.g., causing a cell phone battery to discharge faster). These and other events could make a device willing 10 or not willing to participate in wireless sensing system operations. In some cases, a cell phone running on its battery may not want to participate, but when the cell phone is plugged into a charger, it may be willing to participate. Accordingly, if the cell phone is unplugged, it may indicate to the wireless sensing system to exclude the cell phone from participating; whereas if the cell phone is plugged in, it may indicate to the wireless sensing system to include the cell 15 phone in wireless sensing system operations. In some cases, if a device is under load (e.g., a device streaming audio or video) or busy performing a primary function, the device may not want to participate; whereas when the same device’s load is reduced and participating will not interfere with a primary function, the device may indicate to the wireless sensing system that it is willing to participate. 20

[0058] Example wireless sensing systems are described below in the context of motion detection motion of in the space, motion detection, presencegesture detection,humanandhuman, human tracking, fall detection, speed estimation, detection, 25signratebreathing rate estimation, room occupancy detection, human dynamics monitoring, and other types of motion detection applications). However, the operation, system improvements, and technical advantages achieved when the wireless sensing system is operating as a motion detection 30 system are also applicable in examples where the wireless sensing system is used for another type of wireless sensing application.

[0060] A networkindices a d ic d in the WLA netw k. Fr exmplMulti AP device or a STA deviceay be a n workng devi .

[0061] 5

[006] 10

[0003] A “spae” rfer to nycal ce in which a Wi-Fi sensingm operate.

[0064] A term “sensing area” may refer to a part or subset of a sensing space. For example, if a sensing space represents a house, then an individual room may be a sensing area within 15 that sensing space.

[0065] A term “sensing procedure” may refer to a procedure that allows a high-efficiency (HE) station (STA) or extremely high throughput (EHT) STA to perform sensing. A sensing procedure may be initiated with the establishment of a sensing measurement session, which may be followed by zero or more sensing measurement exchanges, and may be terminated 20 either implicitly or explicitly with a sensing measurement session termination.

[0066] A term “sensing capabilities exchange” may refer to the beginning part of a sensing procedure, during which the sensing capabilities may be exchanged between the sensing STAs. A term “sensing capabilities exchange” may also be referred to as “sensing session setup” or “session setup”. 25

[0067] A term “sensing measurement session” may refer to a set of sensing measurement exchanges that use operational parameters agreed to between a sensing initiator and sensing responder and is identified by a Measurement Session ID. The term “sensing measurement session” may also be referred to as “sensing session” or “sensing measurement setup” or “measurement setup”. The term “Measurement Session ID” may also be referred to as 30 “Measurement Setup ID”.

[0068] A term “sensing measurement exchange” may refer to part of a sensing procedure, during which sensing measurements are performed.

[0069] A term "sensing initiator" may refer to a high-efficiency (HE) station (STA) or extremely high throughput (EHT) STA that initiates a sensing procedure by transmitting a Sensing Measurement Request frame, or a STA initiates a DMG sensing procedure by a Sensing5(HE) orSTA aa a ato athat10or aAreceiver" may refer to a station (STA) that is the intended recipient of PPDUs sent by a sensing transmitter to obtain sensing measurements in either a sensing procedure or a directional multi-gigabit (DMG) sensing procedure.15

[0073] AQ a ss cgr (oth tan omb20 st as part of a or[0“r y etce” PA ”) m fe t a c t d i thcan act as a proxy AP and initiate the forming of a WLAN sensing network among the client devices in the ESS.

[0075] A term “client device” (or “CD”) refers to a piece of software or hardware that 25 requests and receives information or resources from a server. The client device is typically used to access data, services, or applications provided by servers over a network, such as the Internet. For example, client devices include smartphones, laptops, desktop computers, and other devices that may connect to the network and communicate with servers. A client device may be a networking device, non-AP STA or Multi-AP device with a sensing agent (or sensing 30 algorithm) on it.

[0076] A term “sensing link” may refer to a link that traverses a sensing area of interest between two networking devices in a Wi-Fi network.

[0077] A term “normal client devices” (or “NCD”) may refer to a client device which is not the proxy AP client device in the ESS.

[0078] A term “sensing pulse packet” may refer to a packet sent from the client device to its associated AP to indicate that the client device capability and status for sensing.

[0079] A term “BeaconSNR” may refer to the signal-to-noise ratio of the received Beacon frames, in dB. This may be time-averaged over recent history by a vendor-specific smoothing 5 function. (as defined in Table 6-7—ESS Link Parameter Set of Draft P802.11REVme_D5.0).

[0080] A term “DataFrameSNR” may refer to the signal-to-noise ratio of the received Data frames, in dB. This may be time-averaged over recent history by a vendor-specific smoothing function. (as defined in Table 6-7—ESS Link Parameter Set of Draft P802.11REVme_D5.0).

[0081] A term “PACD capability” may refer to a capability to indicate if a client device 10 could be a PACD.

[0082] A term “PACD capable device” may refer to a client device whose PACD capability value is equal to 1.

[0083] A term “current PACD status” may refer to a status to indicate if the client device is the current PACD. 15

[0084] A term “interference profile” may refer to the average noise plus interference power indicator. A medium access control of the average noise plus on a thenotanot(as3.1 of Draft.20 referinof atotoclient25AP. A current associated NCD may be a normal client device associated with the current selected AP before PACD selection or a normal client device switched to the current selected AP before PACD selection for sensing.

[0088] 30AQS a ess ct r ACthom br std pa orssio e iat[ ]5

[0009] “ frmytitwee ait . ( i Aneh thed iugh t ef function definedfor access10 PHYthebe approximately 10 ^s.15 and payload

[0092] not include20 [

[0094] m “ rce u y ra aloofr25 i p D ) c nc a bdca at s nnRU may include a variable number of carriers depending on the mode of the modem.

[0095] A term “tone” may refer to an individual subcarrier in an OFDM signal. A tone may be represented in time domain or frequency domain. In the time domain, a tone may also be referred to as a symbol. In frequency domain, a tone may also be referred to as a subcarrier. 30

[0096] A term “time domain pulse” may refer to a complex number that represents amplitude and phase of discretized energy in time domain. When frequency domain channel state information values are obtained for each tone from a baseband receiver, timepulses may be obtained by performing an inverse fast Fourier transform (IFFT) on the channel state information values.

[0097] A term “sensing goal” may refer to a goal of a sensing activity at a time. A sensing goal is not static and may change at any time. In an example, a sensing goal may require sensing 5 measurements of a specific type, a specific format, or a specific precision, resolution, or accuracy to be available to a sensing algorithm.

[0098] A term “wireless local network (WLAN) sensingor “Wi-Fi sensing session” refer to a periodwhich objects in a physicalmay be probed, detected, and / or characterized. In an example, during a WLAN sensing 10 thereby to theAbeas a

[0099] A term “non-sensing message” may refer to a message which is not primarily related to sensing. In an example, non-sensing messages may include data, management, and control messages. 15

[0100] A term “sensing measurement” may refer to a measurement of a state of a wireless channel between a transmitter device (for example, a sensing transmitter) and a receiver device (for example, a sensing receiver) derived from a sensing transmission.[ t “sensing may t a that20 sensing goal. A sensingmay beonanyin a W F

[0102] Wireless network management (WNM) may provide information on network conditions and may also provide a means to obtain and exchange WLAN sensing information.

[0103] A sensing receiver is a station (STA) that receives sensing transmissions (for example, PPDUs or any other transmission including a data transmission which may be 25 opportunistically used as a sensing transmission) sent by a sensing transmitter and performs sensing measurements as part of a WLAN sensing procedure. An AP is an example of a sensing receiver. In some examples, a STA may also be a sensing receiver.

[0104] A sensing transmitter is a station (STA) that transmits a sensing transmission (for example, PPDUs or any other transmission) used for sensing measurements (for example, 30 channel state information) in a WLAN sensing procedure. In an example, a STA is an example of a sensing transmitter. In some examples, an AP may be a sensing transmitter for Wi-Fi sensing purposes, for example where a STA acts as a sensing receiver.

[0105] A sensing initiator is a station (STA) that initiates a WLAN sensing procedure. The role of sensing initiator may be taken on by a sensing receiver, a sensing transmitter, or a separate device which includes a sensing algorithm (for example, a remote processing device).

[0106] A sensing responder is a station (STA) that participates in a WLAN sensing 5 procedure by a initiator. The role of responder may be taken on by a or atransmitter. Insensing responders take in Fi session.

[0107] A is as AP aIn10ofantennaaofthe SBP procedure, it is possible for a non-AP STA to obtain sensing measurements necessary for detecting and tracking changes in the environment. A sensing by proxy (SBP) responder is an AP that receives or is the intended recipient of an SBP Request 15 frame.

[0108] 20 [ A“stag”re r t ase fa nt a seit in te or trigge n or r s g tra m

[0110] A term “sensing response message” may refer to a message which is included within a sensing transmission from a sensing transmitter to a sensing receiver. A sensing transmission that includes a sensing response message may be used by a sensing receiver to 25 perform a sensing measurement.

[0111] A term “sensing response announcement” may refer to a message that is included within a sensing transmission from a sensing transmitter to a sensing receiver that that a sensing response NDP will follow within a short interframe space (SIFS). An a pe of a sensing response announcement is an NDP announcement, or NDPA. In examples, 30 sensing response NDP may be transmitted using a requested transmission configuration.

[0112] A term “sensing response NDP” may refer to a response transmitted by a sensing transmitter and used for a sensing measurement at a sensing receiver. In examples, a sensing response NDP may be used when a requested transmission configuration is incompatible with transmission parameters required for successful non-sensing message reception. A sensingresponse NPmay beby a sening respnseIn ansensingmaybe implemented with a nulldatasomea sensing be a framedata.5aaalotor ms orsing trasamplingstate of the at the10is a15 andofof aAof aphase (real) component (I) and a quadrature(imaginary) component (Q).

[0115] 20

[0116] A term “full time-domain channel representation information (full TD-CRI)” may25 refer to a series of complex pairs of time domain pulses which are created by performing aninverse transform, such as an IDFT or an IFFT, on CSI values, for example CSI calculated by a baseband receiver.

[0117] A term “filtered time-domain channel representation information (filtered TD- CRI)” may refer to a reduced series of complex pairs of time domain pulses created by applying 30 an algorithm to a full TD-CRI. The algorithm may select some time domain pulses and reject others. The filtered TD-CRI may contain information that relates a selected time domain pulse to the corresponding time domain pulse in the full TD-CRI.

[0118] A term “reconstructed filtered time-domain channel representation information (reconstructed filtered TD-CRI)” may refer to a version of a full TD-CRI created from a filtered TD-CRI.

[0119] A term “channel representation information transmission message” may refer to a 5 message sent by a sensing receiver that has performed a sensing measurement on a sensing transmission, in which the sensing receiver sends CRI to a sensing initiator which may be a sensing transmitter which contains a sensing algorithm or a remote processing device which contains a sensing algorithm.

[0120] A term “reconstructed CSI (R-CSI)” may refer to a representation of original CSI 10 values as measured by the baseband receiver that is reconstructed from a time domain channel representation information (TD-CRI). In an example, R-CSI may be calculated by taking original CSI values (frequency domain), performing an IFFT to translate those values into the time domain, selecting a number of time domain pulses, zeroing or nulling time domain tones that do not include a selected time domain pulse, and performing a fast Fourier transform 15 (FFT). The resulting frequency domain complex values are the R-CSI.

[0121] A term “feature of interest” may refer to an item or state of an item in a sensing space which is positively detected and / or identified by a sensing algorithm.

[0122] A term “sensing imprint” may refer to a steady state or semi-static representation of the propagation channel between a sensing transmitter and a sensing receiver in the sensing 20 space calculated by the sensing receiver in the form of a time domain channel impulse response.

[0123] A term “requested transmission configuration” may refer to transmission parameters a sensing transmitter is requested to use when sending a sensing transmission.

[0124] A term “delivered transmission configuration” may refer to transmission parameters applied by a sensing transmitter to a sensing transmission. 25

[0125] A term “imprint delta” may refer to a single dimension matrix of complex values which represent the difference between a time domain channel impulse response generated by converting a CSI measurement to the time domain using an IFFT, and a stored sensing imprint.

[0126] A term “measurement imprint delta threshold” may refer to minimum difference between a TD-CRI value and the corresponding sensing imprint value for which a sensing 30 receiver or a sensing algorithm considers that there is a change in the propagation channel propagation characteristics.

[0127] A term “measurement imprint delta count” may refer to a number of times which a measurement imprint delta threshold is exceeded before a sensing receiver, or a sensing algorithm considers that there is a change in propagation channel propagation characteristics.

[0128] A term “imprint delta derivative period” may refer to a period during which imprint delta derivatives must remain below an imprint delta derivative threshold before a sensing receiver or a sensing algorithm may determine that a new sensing imprint needs to be calculated. 5

[0129] A term “imprint delta derivative” may refer to a rate of change of the imprint delta over one or more tones and over one or more frames.

[0130] A term “imprint delta derivative threshold” may refer to a maximum value of the imprint delta derivative for which a sensing receiver or a sensing algorithm considers that there is ongoing movement or motion in the sensing space. If the imprint delta derivative drops below 10 the imprint delta derivative threshold, a sensing receiver or a sensing algorithm may determine that a new sensing imprint needs to be calculated.

[0131] A term “steady-state imprint delta threshold” may refer to a maximum difference between a TD-CRI value and a corresponding sensing imprint value for which a sensing receiver or a sensing algorithm considers that the TD-CRI has not returned to its steady-state 15 (i.e., a stored sensing imprint).

[0132] A term “sensing imprint average count” may refer to a number of sensing measurements which may be averaged to generate a sensing imprint.

[0133] A term “steering matrix configuration” may refer to a matrix of complex values representing real and complex phases required to pre-condition one or more antennas of a radio 20 frequency (RF) transmission signal chain for each transmit signal. Application of a steering matrix configuration (for example, by a spatial mapper) enables beamforming and beam- steering.

[0134] A term “spatial mapper” may refer to a signal processing element that adjusts the amplitude and phase of a signal input to an RF transmission chain in a sensing transmitter. A 25 spatial mapper may include elements to process the signal to each RF chain implemented. The operation carried out may be called spatial mapping. The output of a spatial mapper is one or more spatial streams.

[0135] A mesh network or a wireless mesh network may refer to a communications network (e.g., WLAN) made up of radio nodes (e.g., mesh stations or mesh STAs, mesh clients, 30 or Multi-AP devices, etc.) organized in a mesh topology. In examples, the mesh network may also be referred to as “Mesh”.

[0136] A sensing controller is a controller that facilitates and coordinates WLAN sensing related connections and activities.

[0137] A Multi-AP device may refer to a physical device of a mesh network that may act as both a station and an AP or a device that has Backhaul STA module for backhaul link connection and Fronthaul AP module for fronthaul link connection.

[0138] A term “Multi-AP Network” or “Multi-AP Network Deployment”, or “Mesh BSS” 5 may refer to a collection of interconnected physical devices.

[0139] A term “mesh root node” may refer to a Multi-AP device with a Multi-AP controller in a mesh network. In examples, a backhaul of the mesh root node is connected to a wide area network (WAN).

[0140] A term “leaf node” may refer to a Multi-AP device without a Multi-AP controller 10 in the mesh network. The leaf node may connect to the mesh root node directly or via other leaf nodes.

[0141] A term “hop” in a mesh network may refer to a backhaul connection between two Multi-AP devices.

[0142] A term “mesh network configuration option (MNCO)” may refer to a possible way 15 to configure backhaul links in the mesh network.

[0143] A term “sensing preferred MNCO” may refer to an MNCO that is best suited or adequately suited to sensing according to one or more established criteria. In examples, a sensing preferred MNCO must also be adequately suited for data communications.

[0144] A term “preferred sensing link” may refer to a link that traverses a sensing area of 20 interest between two multi-AP devices in a mesh network. In an example, the preferred sensing link may be determined by a sensing algorithm or a sensing controller to be the best sensing link by some criteria.

[0145] A term “sensing PPDU” may refer to a customized data packet with one or more training fields on which sensing measurements can be made and a header and data field portion 25 which contain Motion Information elements to be shared with other networked devices in the Wi-Fi network.

[0146] A term “Out-of-BSS (OBSS)” may be used by IEEE P802.11bf to describe communications between STAs which are not part of a BSS (and may or may not be part of an ESS). In the case of WLAN sensing, OBSS may describe sensing messages and sensing 30 transmissions made between STAs which are not part of a BSS but which may generate useful sensing measurements.

[0147] A term “BSS” may refer to a collection of an AP STA and non-AP STAs which are associated together at the PHY / MAC layer to form a wireless network. The BSS includes a single Station (STA) acting as an Access Point (AP or AP STA) and one or more STAs connected to and controlled by AP device (non-AP STA, or simply STA where the access point 5 is AP). A BSS is identified in IEEE 802.11 by a BSSID.

[0148] For purposes of reading the description of the various embodiments below, the following descriptions of the sections of the specifications and their respective contents may be helpful:

[0149] Section A describes a wireless communications system, wireless transmissions and 10 sensing measurements which may be useful for practicing embodiments described herein.

[0150] Section B describes systems and methods that are useful for a wireless sensing system configurated to establish a Wi-Fi sensing network and make sensing measurements.

[0151] Section C describes embodiments of systems and methods that are useful for establishing a Wi-Fi sensing network carried out by a client device. 15 A. Wireless communications system, wireless transmissions, and sensing measurements

[0152] FIG.1 illustrates wireless communication system 100. Wireless communication system 100 includes three wireless communication devices: first wireless communication device 102A, second wireless communication device 102B, and third wireless communication 20 device 102C. Wireless communication system 100 may include additional wireless communication devices and other components (e.g., additional wireless communication devices, one or more network servers, network routers, network switches, cables, or other communication links, etc.).

[0153] Wireless communication devices 102A, 102B, 102C can operate in a wireless 25 network, for example, according to a wireless network standard or another type of wireless communication protocol. For example, the wireless network may be configured to operate as a wireless local area network (WLAN), a personal area network (PAN), a metropolitan area network (MAN), or another type of wireless network. Examples of WLANs include networks configured to operate according to one or more of the 802.11 family of standards developed by 30 IEEE (e.g., Wi-Fi networks), and others. Examples of PANs include networks that operate according to short-range communication standards (e.g., Bluetooth®., Near Field Communication (NFC), ZigBee), millimeter wave communications, and others.

[0154] In some implementations, wireless communication devices 102A, 102B, 102C may be configured to communicate in a cellular network, for example, according to a cellular network standard. Examples of cellular networks include networks configured according to 2G standards such as Global System for Mobile (GSM) and Enhanced Data rates for GSM 5 Evolution (EDGE) or EGPRS; 3G standards such as code division multiple access (CDMA), wideband code division multiple access (WCDMA), Universal Mobile Telecommunications System (UMTS), and time division synchronous code division multiple access (TD-SCDMA); 4G standards such as Long-Term Evolution (LTE) and LTE-Advanced (LTE-A); 5G standards, and others. 10

[0155] In the example shown in FIG.1, wireless communication devices 102A, 102B, 102C can be, or they may include standard wireless network components. For example, wireless communication devices 102A, 102B, 102C may be commercially-available Wi-Fi APs or another type of wireless access point (WAP) performing one or more operations as described herein that are embedded as instructions (e.g., software or firmware) on the modem of the 15 WAP. In some cases, wireless communication devices 102A, 102B, 102C may be nodes of a wireless mesh network, such as, for example, a commercially-available mesh network system (e.g., Plume Wi-Fi, Google Wi-Fi, Qualcomm Wi-Fi SON, etc.). In some cases, wireless communication devices 102A, 102B, 102C acting as nodes of a mesh network system may adhere to a mesh networking standard such as Wi-Fi Alliance EasyMesh or IEEE P802.11s. In 20 some cases, another type of standard or conventional Wi-Fi transmitter device may be used. In some instances, one or more of wireless communication devices 102A, 102B, 102C may be implemented as WAPs in a mesh network, while other wireless communication device(s) 102A, 102B, 102C are implemented as leaf devices (e.g., mobile devices, smart devices, etc.) that access the mesh network through one of the WAPs. In some cases, one or more of wireless 25 communication devices 102A, 102B, 102C is a mobile device (e.g., a smartphone, a smart watch, a tablet, a laptop computer, etc.), a wireless-enabled device (e.g., a smart thermostat, a Wi-Fi enabled camera, a smart TV), or another type of device that communicates in a wireless network.

[0156] Wireless communication devices 102A, 102B, 102C may be implemented without 30 Wi-Fi components; for example, other types of standard or non-standard wireless communication may be used for motion detection. In some cases, wireless communication devices 102A, 102B, 102C can be, or they may be part of, a dedicated motion detection system. For example, the dedicated motion detection system can include a hub device and one or morebeacon devices (as remote sensor devices), and wireless communication devices 102A, 102B, 102C can be either a hub device or a beacon device in the motion detection system.

[0157] As shown in FIG.1, wireless communication device 102C includes modem 112, processor 114, memory 116, and power unit 118; any of wireless communication devices 5 102A, 102B, 102C in wireless communication system 100 may include the same, additional, or different components, and the components may be configured to operate as shown in FIG. 1 or in another manner. In some implementations, modem 112, processor 114, memory 116, and power unit 118 of a wireless communication device are housed together in a common housing or other assembly. In some implementations, one or more of the components of a 10 wireless communication device can be housed separately, for example, in a separate housing or other assembly.

[0158] Modem 112 can communicate (receive, transmit, or both) wireless signals. For example, modem 112 may be configured to communicate RF signals formatted according to a wireless communication standard (e.g., Wi-Fi or Bluetooth). Modem 112 may be implemented 15 as the example wireless network modem 112 shown in FIG.1, or may be implemented in another manner, for example, with other types of components or subsystems. In some implementations, modem 112 includes a radio subsystem and a baseband subsystem. In some cases, the baseband subsystem and radio subsystem can be implemented on a common chip or chipset, or they may be implemented in a card or another type of assembled device. The 20 baseband subsystem can be coupled to the radio subsystem, for example, by leads, pins, wires, or other types of connections.

[0159] In some cases, a radio subsystem in modem 112 can include one or more antennas and RF circuitry. The RF circuitry can include, for example, circuitry that filters, amplifies, or otherwise conditions analog signals, circuitry that up-converts baseband signals to RF signals, 25 circuitry that down-converts RF signals to baseband signals, etc. Such circuitry may include, for example, filters, amplifiers, mixers, a local oscillator, etc. The radio subsystem can be configured to communicate radio frequency wireless signals on the wireless communication channels. As an example, the radio subsystem may include a radio chip, an RF front end, and one or more antennas. A radio subsystem may include additional or different components. In 30 some implementations, the radio subsystem can be or may include the radio electronics (e.g., RF front end, radio chip, or analogous components) from a conventional modem, for example, from a Wi-Fi modem, pico base station modem, etc. In some implementations, the antenna includes multiple antennas.

[0160] In some cases, a baseband subsystem in modem 112 can include, for example, digital electronics configured to process digital baseband data. As an example, the baseband subsystem may include a baseband chip. A baseband subsystem may include additional or different components. In some cases, the baseband subsystem may include a digital signal 5 processor (DSP) device or another type of processor device. In some cases, the baseband system includes digital processing logic to operate the radio subsystem, to communicate wireless network traffic through the radio subsystem, to detect motion based on motion detection signals received through the radio subsystem or to perform other types of processes. For instance, the baseband subsystem may include one or more chips, chipsets, or other types 10 of devices that are configured to encode signals and deliver the encoded signals to the radio subsystem for transmission, or to identify and analyze data encoded in signals from the radio subsystem (e.g., by decoding the signals according to a wireless communication standard, by processing the signals according to a motion detection process, or otherwise).

[0161] In some instances, the radio subsystem in modem 112 receives baseband signals 15 from the baseband subsystem, up-converts the baseband signals to RF signals, and wirelessly transmits the RF signals (e.g., through an antenna). In some instances, the radio subsystem in modem 112 wirelessly receives RF signals (e.g., through an antenna), down-converts the RF to baseband signals, and sends the baseband signals to the baseband subsystem. The signals exchanged between the radio subsystem and the baseband subsystem may be digital or analog 20 signals. In some examples, the baseband subsystem includes conversion circuitry (e.g., a digital-to-analog converter, an analog-to-digital converter) and exchanges analog signals with the radio subsystem. In some examples, the radio subsystem includes conversion circuitry (e.g., a digital-to-analog converter, an analog-to-digital converter) and exchanges digital signals with the baseband subsystem. 25

[0162] In some cases, the baseband subsystem of modem 112 can communicate wireless network traffic (e.g., data packets) in the wireless communication network through the radio subsystem on one or more network traffic channels. The baseband subsystem of modem 112 may also transmit or receive (or both) signals (e.g., motion probe signals or motion detection signals) through the radio subsystem on a dedicated wireless communication channel. In some 30 instances, the baseband subsystem generates motion probe signals for transmission, for example, to probe a space for motion. In some instances, the baseband subsystem processes the received motion detection signals (signals based on motion probe signals transmitted through the space), for example, to detect motion of an object in a space.

[0163] Processor 114 can execute instructions, for example, to generate output data based on data inputs. The instructions can include programs, codes, scripts, or other types of data stored in memory. Additionally, or alternatively, the instructions can be encoded as pre- programmed or re-programmable logic circuits, logic gates, or other types of hardware or 5 firmware components. Processor 114 may be or include a general-purpose microprocessor, as a specialized co-processor or another type of data processing apparatus. In some cases, processor 114 performs high level operation of the wireless communication device 102C. For example, processor 114 may be configured to execute or interpret software, scripts, programs, functions, executables, or other instructions stored in memory 116. In some implementations, 10 processor 114 may be included in modem 112.

[0164] Memory 116 can include computer-readable storage media, for example, a volatile memory device, a non-volatile memory device, or both. Memory 116 can include one or more read-only memory devices, random-access memory devices, buffer memory devices, or a combination of these and other types of memory devices. In some instances, one or more 15 components of the memory can be integrated or otherwise associated with another component of wireless communication device 102C. Memory 116 may store instructions that are executable by processor 114. For example, the instructions may include instructions for time- aligning signals using an interference buffer and a motion detection buffer, such as through one or more of the operations of the example processes herein disclosed. 20

[0165] Power unit 118 provides power to the other components of wireless communication device 102C. For example, the other components may operate based on electrical power provided by power unit 118 through a voltage bus or other connection. In some implementations, power unit 118 includes a battery or a battery system, for example, a rechargeable battery. In some implementations, power unit 118 includes an adapter (e.g., an 25 alternating current (AC) adapter) that receives an external power signal (from an external source) and converts the external power signal to an internal power signal conditioned for a component of wireless communication device 102C. Power unit 118 may include other components or operate in another manner.

[0166] In the example shown in FIG.1, wireless communication devices 102A, 102B 30 transmit wireless signals (e.g., according to a wireless network standard, a motion detection protocol, or otherwise). For instance, wireless communication devices 102A, 102B may broadcast wireless motion probe signals (e.g., reference signals, beacon signals, status signals, etc.), or they may send wireless signals addressed to other devices (e.g., a user equipment, a client device, a server, etc.), and the other devices (not shown) as well as wirelesscommunication device 102C may receive the wireless signals transmitted by wireless communication devices 102A, 102B. In some cases, the wireless signals transmitted by wireless communication devices 102A, 102B are repeated periodically, for example, according to a wireless communication standard or otherwise. 5

[0167] In the example shown, wireless communication device 102C processes the wireless signals from wireless communication devices 102A, 102B to detect motion of an object in a space accessed by the wireless signals, to determine a location of the detected motion, or both. For example, wireless communication device 102C may perform one or more operations of the example processes described below with respect to FIG.18 to FIG.23, or another type of 10 process for detecting motion or determining a location of detected motion. The space accessed by the wireless signals can be an indoor or outdoor space, which may include, for example, one or more fully or partially enclosed areas, an open area without enclosure, etc. The space can be or can include an interior of a room, multiple rooms, a building, or the like. In some cases, the wireless communication system 100 can be modified, for instance, such that wireless 15 communication device 102C can transmit wireless signals and wireless communication devices 102A, 102B can process the wireless signals from wireless communication device 102C to detect motion or determine a location of detected motion.

[0168] The wireless signals used for motion detection can include, for example, a beacon signal (e.g., Bluetooth Beacons, Wi-Fi Beacons, other wireless beacon signals), another20 standard signal generated for other purposes according to a wireless network standard, or non- standard signals (e.g., random signals, reference signals, etc.) generated for motion detection or other purposes. In examples, motion detection may be carried out by analyzing one or more training fields carried by the wireless signals or by analyzing other data carried by the signal. In some examples data will be added for the express purpose of motion detection or the data 25 used will nominally be for another purpose and reused or repurposed for motion detection. In some examples, the wireless signals propagate through an object (e.g., a wall) before or after interacting with a moving object, which may allow the moving object's movement to be detected without an optical line-of-sight between the moving object and the transmission or receiving hardware. Based on the received signals, wireless communication device 102C may 30 generate motion detection data. In some instances, wireless communication device 102C may communicate the motion detection data to another device or system, such as a security system, which may include a control center for monitoring movement within a space, such as a room, building, outdoor area, etc.

[0169] In some implementations, wireless communication devices 102A, 102B can be modified to transmit motion probe signals (which may include, e.g., a reference signal, beacon signal, or another signal used to probe a space for motion) on a separate wireless communication channel (e.g., a frequency channel or coded channel) from wireless network 5 traffic signals. For example, the modulation applied to the payload of a motion probe signal and the type of data or data structure in the payload may be known by wireless communication device 102C, which may reduce the amount of processing that wireless communication device 102C performs for motion sensing. The header may include additional information such as, for example, an indication of whether motion was detected by another device in wireless 10 communication system 100, an indication of the modulation type, an identification of the device transmitting the signal, etc.

[0170] In the example shown in FIG.1, wireless communication system 100 is a wireless mesh network, with wireless communication links between each of wireless communication devices 102. In the example shown, the wireless communication link between wireless 15 communication device 102C and wireless communication device 102A can be used to probe motion detection field 110A, the wireless communication link between wireless communication device 102C and wireless communication device 102B can be used to probe motion detection field 110B, and the wireless communication link between wireless communication device 102A and wireless communication device 102B can be used to probe 20 motion detection field 110C. In some instances, each wireless communication device 102 detects motion in motion detection fields 110 accessed by that device by processing received signals that are based on wireless signals transmitted by wireless communication devices 102 through motion detection fields 110. For example, when person 106 shown in FIG.1 moves in motion detection field 110A and motion detection field 110C, wireless communication devices 25 102 may detect the motion based on signals they receive that are based on wireless signals transmitted through respective motion detection fields 110. For instance, wireless communication device 102A can detect motion of person 106 in motion detection fields 110A, 110C, wireless communication device 102B can detect motion of person 106 in motion detection field 110C, and wireless communication device 102C can detect motion of person 30 106 in motion detection field 110A.

[0171] In some instances, motion detection fields 110 can include, for example, air, solid materials, liquids, or another medium through which wireless electromagnetic signals may propagate. In the example shown in FIG.1, motion detection field 110A provides a wireless communication channel between wireless communication device 102A and wirelesscommunication device 102C, motion detection field 110B provides a wireless communication channel between wireless communication device 102B and wireless communication device 102C, and motion detection field 110C provides a wireless communication channel between wireless communication device 102A and wireless communication device 102B. In some 5 aspects of operation, wireless signals transmitted on a wireless communication channel (separate from or shared with the wireless communication channel for network traffic) are used to detect movement of an object in a space. The objects can be any type of static or moveable object and can be living or inanimate. For example, the object can be a human (e.g., person 106 shown in FIG.1), an animal, an inorganic object, or another device, apparatus, or assembly, an 10 object that defines all or part of the boundary of a space (e.g., a wall, door, window, etc.), or another type of object. In some implementations, motion information from the wireless communication devices may be analyzed to determine a location of the detected motion. For example, as described further below, one of wireless communication devices 102 (or another device communicably coupled to wireless communications devices 102) may determine that 15 the detected motion is nearby a particular wireless communication device.

[0172] FIG. 2A and FIG. 2B are diagrams showing example wireless signals communicated between wireless communication devices 204A, 204B, 204C. Wireless communication devices 204A, 204B, 204C can be, for example, wireless communication devices 102A, 102B, 102C shown in FIG.1, or other types of wireless communication devices. 20 Wireless communication devices 204A, 204B, 204C transmit wireless signals through space 200. Space 200 can be completely or partially enclosed or open at one or more boundaries. In an example, space 200 may be a sensing space. Space 200 can be or can include an interior of a room, multiple rooms, a building, an indoor area, outdoor area, or the like. First wall 202A, second wall 202B, and third wall 202C at least partially enclose space 200 in the example 25 shown.

[0173] In the example shown in FIG.2A and FIG.2B, wireless communication device 204A is operable to transmit wireless signals repeatedly (e.g., periodically, intermittently, at scheduled, unscheduled or random intervals, etc.). Wireless communication devices 204B, 204C are operable to receive signals based on those transmitted by wireless communication 30 device 204A. Wireless communication devices 204B and 204C each have a modem (e.g., modem 112 shown in FIG.1) that is configured to process received signals to detect motion of an object in space 200.

[0174] As shown, an object is in first position 214A in FIG.2A, and the object has moved to second position 214B in FIG.2B. In FIG.2A and FIG.2B, the moving object in space 200is represented as a human, but the moving object can be another type of object. For example, the moving object can be an animal, an inorganic object (e.g., a system, device, apparatus, or assembly), an object that defines all or part of the boundary of space 200 (e.g., a wall, door, window, etc.), or another type of object. 5

[0175] As shown in FIG.2A and FIG.2B, multiple example paths of the wireless signals transmitted from wireless communication device 204A are illustrated by dashed lines. Along first signal path 216, the wireless signal is transmitted from wireless communication device 204A and reflected off first wall 202A toward the wireless communication device 204B. Along second signal path 218, the wireless signal is transmitted from the wireless communication 10 device 204A and reflected off second wall 202B and first wall 202A toward wireless communication device 204C. Along third signal path 220, the wireless signal is transmitted from the wireless communication device 204A and reflected off second wall 202B toward wireless communication device 204C. Along fourth signal path 222, the wireless signal is transmitted from the wireless communication device 204A and reflected off third wall 202C 15 toward the wireless communication device 204B.

[0176] In FIG.2A, along fifth signal path 224A, the wireless signal is transmitted from wireless communication device 204A and reflected off the object at first position 214A toward wireless communication device 204C. Between FIG.2A and FIG.2B, a surface of the object moves from first position 214A to second position 214B in space 200 (e.g., some distance away 20 from first position 214A). In FIG.2B, along sixth signal path 224B, the wireless signal is transmitted from wireless communication device 204A and reflected off the object at second position 214B toward wireless communication device 204C. Sixth signal path 224B depicted in FIG.2B is longer than fifth signal path 224A depicted in FIG.2A due to the movement of the object from first position 214A to second position 214B. In some examples, a signal path 25 can be added, removed, or otherwise modified due to movement of an object in a space.

[0177] The example wireless signals shown in FIG. 2A and FIG. 2B may experience attenuation, frequency shifts, phase shifts, or other effects through their respective paths and may have portions that propagate in another direction, for example, through the first, second and third walls 202A, 202B, and 202C. In some examples, the wireless signals are radio 30 frequency (RF) signals. The wireless signals may include other types of signals.

[0178] In the example shown in FIG.2A and FIG.2B, wireless communication device 204A can repeatedly transmit a wireless signal. In particular, FIG.2A shows the wireless signal being transmitted from wireless communication device 204A at a first time, and FIG.2B shows the same wireless signal being transmitted from wireless communication device 204A at asecond, later time. The transmitted signal can be transmitted continuously, periodically, at random or intermittent times or the like, or a combination thereof. The transmitted signal can have a number of frequency components in a frequency bandwidth. The transmitted signal can be transmitted from wireless communication device 204A in an omnidirectional manner, in a directional manner or otherwise. In the example shown, the wireless signals traverse multiple respective paths in space 200, and the signal along each path may become attenuated due to path losses, scattering, reflection, or the like and may have a phase or frequency offset.

[0179] As shown in FIG.2A and FIG.2B, the signals from first to sixth paths 216, 218, 220, 222, 224A, and 224B combine at wireless communication device 204C and wireless communication device 204B to form received signals. Because of the effects of the multiple paths in space 200 on the transmitted signal, space 200 may be represented as a transfer function (e.g., a filter) in which the transmitted signal is input, and the received signal is output. When an object moves in space 200, the attenuation or phase offset affected upon a signal in a signal path can change, and hence, the transfer function of space 200 can change. Assuming the same wireless signal is transmitted from wireless communication device 204A, if the transfer function of space 200 changes, the output of that transfer function – the received signal – will also change. A change in the received signal can be used to detect movement of an object.

[0180] Mathematically, a transmitted signal ^^(^^)transmitted from the first wireless communication device 204A may be described according to Equation (1): ^^(^^) = ∑^ ^ୀି^^^^^^^ఠ^௧…. (1)where ^^^represents the frequency of nth frequency component of the transmitted signal, ^^^represents the complex coefficient of the nth frequency component, and ^^ represents time. With the ^^(^^) being transmitted from the first wireless communication device 204A, an output signal ^^^(^^)from a path, ^^, may be :….where ^^^,^represents an attenuation factor (or channel response; e.g., due to scattering, reflection, and path losses) for the nth frequency component along ^^, and ^^^,^represents the phase of the signal for nth frequency component along ^^. Then, the received signal, ^^, at a wireless communication device can be described as the summation of all output signals ^^^(^^) from all paths to the wireless communication device, which is shown in Equation (3): ^^ = ∑^ ^^^(^^) …. (3)

[0181] SubstitutingEquation (4): ^^ = ∑^∑^ ^ୀି^൫^^^,^^^^థ^,ೖ൯^^^^^^ఠ^௧…. (4)

[0182] ^^ at a wireless communication device can then be analyzed. ^^ at a wireless communication device can be transformed to the frequency domain, for example, using a fast Fourier transform (FFT) or another type of algorithm. The transformed signal can represent ^^ as a series of ^^ complex values, one for each of the respective frequency components (at the ^^ frequencies ^^^). For a frequency component at frequency ^^^, a complex value, ^^^, may be represented as follows in Equation (5): ^^^ =^

[0183] ^^ for a g^ iven ^^^phase offset of the received signal at ^^^. When an object moves in the space, ^^^changes due to ^^^,^of the space changing. Accordingly, a change detected in the channel response can be indicative of movement of an object within the communication channel. In some instances, noise, interference, or other phenomena can influence the channel response detected by the receiver, and the motion detection system can reduce or isolate such influences to improve the accuracy and quality of motion detection capabilities. In some implementations, the overall channel response can be represented as follows in Equation (6): ^

[0184] In some instances, the channel response, ℎ^^, for a space can be determined, for example, based on the mathematical theory of estimation. For instance, a reference signal, ^^^^^, can be modified with candidate ℎ^^, and then a maximum likelihood approach can be used to select the candidate channel which gives best match to the received signal (^^^^௩ௗ). In some cases, an estimated received signal (^^^^^௩ௗ) is obtained from the convolution of ^^^^^with the candidate ℎ^^, and then the channel coefficients of ℎ^^are varied to minimize the squared error of ^^^^^௩ௗ. This can be illustrated as follows in :….with the optimization criterion…

[0185] The minimizing, or optimizing, process can utilize an adaptive filtering technique, such as least mean squares (LMS), recursive least squares (RLS), batch least squares (BLS), etc. The channel response can be a finite impulse response (FIR) filter, infinite impulse response (IIR) filter, or the like. As shown in the equation above, the received signal can be considered as a convolution of the reference signal and the channel response. The convolution operation means that the channel coefficients possess a degree of correlation with each of thedelayed replicas of the reference signal. The convolution operation as shown in the equation above, therefore shows that the received signal appears at different delay points, each delayed replica being weighted by the channel coefficient.

[0186] FIG.3A and FIG.3B are plots showing examples of channel responses 360, 370 5 computed from the wireless signals communicated between wireless communication devices 204A, 204B, 204C in FIG.2A and FIG.2B. FIG.3A and FIG.3B also show frequency domain representation 350 of an initial wireless signal transmitted by wireless communication device 204A. In the examples shown, channel response 360 in FIG.3A represents the signals received by wireless communication device 204B when there is no motion in space 200, and channel 10 response 370 in FIG.3B represents the signals received by wireless communication device 204B in FIG.2B after the object has moved in space 200.

[0187] In the example shown in FIG.3A and FIG.3B, for illustration purposes, wireless communication device 204A transmits a signal that has a flat frequency profile (the magnitude of each frequency component, ^^^, ^^ଶand ^^ଷis the same), as shown in frequency domain 15 representation 350. Because of the interaction of the signal with space 200 (and the objects therein), the signals received at wireless communication device 204B that are based on the signal sent from wireless communication device 204A are different from the transmitted signal. In this example, where the transmitted signal has a flat frequency profile, the received signal represents the channel response of space 200. As shown in FIG.3A and FIG.3B, channel 20 responses 360, 370 are different from frequency domain representation 350 of the transmitted signal. When motion occurs in space 200, a variation in the channel response will also occur. For example, as shown in FIG.3B, channel response 370 that is associated with motion of object in space 200 varies from channel response 360 that is associated with no motion in space 200. 25

[0188] Furthermore, as an object moves within space 200, the channel response may vary from channel response 370. In some cases, space 200 can be divided into distinct regions and the channel responses associated with each region may share one or more characteristics (e.g., shape), as described below. Thus, motion of an object within different distinct regions can be distinguished, and the location of detected motion can be determined based on an analysis of 30 channel responses.

[0189] FIG.4A and FIG.4B are diagrams showing example channel responses 401, 403 associated with motion of object 406 in distinct regions 408, 412 of space 400. In the examples shown, space 400 is a building, and space 400 is divided into a plurality of distinct regions – first region 408, second region 410, third region 412, fourth region 414, and fifth region 416.Space 400 may include additional or fewer regions, in some instances. As shown in FIG.4A and FIG.4B, the regions within space 400 may be defined by walls between rooms. In addition, the regions may be defined by ceilings between floors of a building. For example, space 400 may include additional floors with additional rooms. In addition, in some instances, the 5 plurality of regions of a space can be or include a number of floors in a multistory building, a number of rooms in the building, or a number of rooms on a particular floor of the building. In the example shown in FIG.4A, an object located in first region 408 is represented as person 406, but the moving object can be another type of object, such as an animal or an inorganic object. 10

[0190] In the example shown, wireless communication device 402A is located in fourth region 414 of space 400, wireless communication device 402B is located in second region 410 of space 400, and wireless communication device 402C is located in fifth region 416 of space 400. Wireless communication devices 402 can operate in the same or similar manner as wireless communication devices 102 of FIG.1. For instance, wireless communication devices 15 402 may be configured to transmit and receive wireless signals and detect whether motion has occurred in space 400 based on the received signals. As an example, wireless communication devices 402 may periodically or repeatedly transmit motion probe signals through space 400, and receive signals based on the motion probe signals. Wireless communication devices 402 can analyze the received signals to detect whether an object has moved in space 400, such as, 20 for example, by analyzing channel responses associated with space 400 based on the received signals. In addition, in some implementations, wireless communication devices 402 can analyze the received signals to identify a location of detected motion within space 400. For example, wireless communication devices 402 can analyze characteristics of the channel response to determine whether the channel responses share the same or similar characteristics 25 to channel responses known to be associated with first to fifth regions 408, 410, 412, 414, 416 of space 400.

[0191] In the examples shown, one (or more) of wireless communication devices 402 repeatedly transmits a motion probe signal (e.g., a reference signal) through space 400. The motion probe signals may have a flat frequency profile in some instances, wherein the 30 magnitude of ^^^, ^^ଶand ^^ଷis the same or nearly the same. For example, the motion probe signals may have a frequency response similar to frequency domain representation 350 shown in FIG.3A and FIG.3B. The motion probe signals may have a different frequency profile in some instances. Because of the interaction of the reference signal with space 400 (and the objects therein), the signals received at another wireless communication device 402 that arebased on the motion probe signal transmitted from the other wireless communication device 402 are different from the transmitted reference signal.

[0192] Based on the received signals, wireless communication devices 402 can determine a channel response for space 400. When motion occurs in distinct regions within the space, 5 distinct characteristics may be seen in the channel responses. For example, while the channel responses may differ slightly for motion within the same region of space 400, the channel responses associated with motion in distinct regions may generally share the same shape or other characteristics. For instance, channel response 401 of FIG.4A represents an example channel response associated with motion of object 406 in first region 408 of space 400, while 10 channel response 403 of FIG.4B represents an example channel response associated with motion of object 406 in third region 412 of space 400. Channel responses 401, 403 are associated with signals received by the same wireless communication device 402 in space 400.

[0193] FIG.4C and FIG.4D are plots showing channel responses 401, 403 of FIG.4A and FIG.4B overlaid on channel response 460 associated with no motion occurring in space 400. 15 In the example shown, wireless communication device 402 transmits a motion probe signal that has a flat frequency profile as shown in frequency domain representation 450. When motion occurs in space 400, a variation in the channel response will occur relative to channel response 460 associated with no motion, and thus, motion of an object in space 400 can be detected by analyzing variations in the channel responses. In addition, a relative location of the 20 detected motion within space 400 can be identified. For example, the shape of channel responses associated with motion can be compared with reference information (e.g., using a trained artificial intelligence (AI) model) to categorize the motion as having occurred within a distinct region of space 400.

[0194] When there is no motion in space 400 (e.g., when object 406 is not present), 25 wireless communication device 402 may compute channel response 460 associated with no motion. Slight variations may occur in the channel response due to a number of factors; however, multiple channel responses 460 associated with different periods of time may share one or more characteristics. In the example shown, channel response 460 associated with no motion has a decreasing frequency profile (the magnitude of each of ^^^, ^^ଶand ^^ଷis less than 30 the previous). The profile of channel response 460 may differ in some instances (e.g., based on different room layouts or placement of wireless communication devices 402).

[0195] When motion occurs in space 400, a variation in the channel response will occur. For instance, in the examples shown in FIG.4C and FIG.4D, channel response 401 associated with motion of object 406 in first region 408 differs from channel response 460 associated withno motion and channel response 403 associated with motion of object 406 in third region 412 differs from channel response 460 associated with no motion. Channel response 401 has a concave-parabolic frequency profile (the magnitude of the middle frequency component, ^^ଶ, is less than the outer frequency components ^^^and ^^ଷ), while channel response 403 has a convex- asymptotic frequency profile (the magnitude of the middle frequency component ^^ଶis greater than the outer frequency components, ^^^and ^^ଷ). The profiles of channel responses 401, 403 may differ in some instances (e.g.,different room layouts or placement of the wireless communication devices 402).

[0196] Analyzing channel responses may be considered similar to analyzing a digital filter. A channel response may be formed through the reflections of objects in a space as well as reflections created by a moving or static human. When a reflector (e.g., a human) moves, it changes the channel response. This may translate to a change in equivalent taps of a digital filter, which can be thought of as having poles and zeros (poles amplify the frequency components of a channel response and appear as peaks or high points in the response, while zeros attenuate the frequency components of a channel response and appear as troughs, low points, or nulls in the response). A changing digital filter can be characterized by the locations of its peaks and troughs, and a channel response may be characterized similarly by its peaks and troughs. For example, in some implementations, analyzing nulls and peaks in the frequency components of a channel response (e.g., by marking their location on the frequency axis and their magnitude), motion can be detected.

[0197] In some implementations, a time series aggregation can be used to detect motion. A time series aggregation may be performed by observing the features of a channel response over a moving window and aggregating the windowed result by using statistical measures (e.g., mean, variance, principal components, etc.). During instances of motion, the characteristic digital-filter features would be displaced in location and flip-flop between some values due to the continuous change in the scattering scene. That is, an equivalent digital filter exhibits a range of values for its peaks and nulls (due to the motion). By looking at this range of values, unique profiles (in examples profiles may also be referred to as signatures) may be identified for distinct regions within a space.

[0198] In some implementations, an AI model may be used to process data. AI models may be of a variety of types, for example linear regression models, logistic regression models, linear discriminant analysis models, decision tree models, naïve bayes models, K-nearest neighbors models, learning vector quantization models, support vector machines, bagging andrandom forest models, and deep neural networks. In general, all AI models aim to learn a function which provides the most precise correlation between input values and output values and are trained using historic sets of inputs and outputs that are known to be correlated. In examples, artificial intelligence may also be referred to as machine learning. 5

[0199] In some implementations, the profiles of the channel responses associated with motion in distinct regions of space 400 can be learned. For example, machine learning may be used to categorize channel response characteristics with motion of an object within distinct regions of a space. In some cases, a user associated with wireless communication devices 402 (e.g., an owner or other occupier of space 400) can assist with the learning process. For 10 instance, referring to the examples shown in FIG.4A and FIG.4B, the user can move in each of first to fifth regions 408, 410, 412, 414, 416 during a learning phase and may indicate (e.g., through a user interface on a mobile computing device) that he / she is moving in one of the particular regions in space 400. For example, while the user is moving through first region 408 (e.g., as shown in FIG.4A) the user may indicate on a mobile computing device that he / she is 15 in first region 408 (and may name the region as “bedroom”, “living room”, “kitchen”, or another type of room of a building, as appropriate). Channel responses may be obtained as the user moves through the region, and the channel responses may be “tagged” with the user's indicated location (region). The user may repeat the same process for the other regions of space 400. The term “tagged” as used herein may refer to marking and identifying channel responses 20 with the user's indicated location or any other information.

[0200] The tagged channel responses can then be processed (e.g., by machine learning software) to identify unique characteristics of the channel responses associated with motion in the distinct regions. Once identified, the identified unique characteristics may be used to determine a location of detected motion for newly computed channel responses. For example, 25 an AI model may be trained using the tagged channel responses, and once trained, newly computed channel responses can be input to the AI model, and the AI model can output a location of the detected motion. For example, in some cases, mean, range, and absolute values are input to an AI model. In some instances, magnitude and phase of the complex channel response itself may be input as well. These values allow the AI model to design arbitrary front- 30 end filters to pick up the features that are most relevant to making accurate predictions with respect to motion in distinct regions of a space. In some implementations, the AI model is trained by performing a stochastic gradient descent. For instance, channel response variations that are most active during a certain zone may be monitored during the training, and the specific channel variations may be weighted heavily (by training and adapting the weights in the firstlayer to correlate with those shapes, trends, etc.). The weighted channel variations may be used to create a metric that activates when a user is present in a certain region.

[0201] For extracted features like channel response nulls and peaks, a time-series (of the nulls / peaks) may be created using an aggregation within a moving window, taking a snapshot 5 of few features in the past and present, and using that aggregated value as input to the network. Thus, the network, while adapting its weights, will be trying to aggregate values in a certain region to cluster them, which can be done by creating a logistic classifier-based decision surfaces. The decision surfaces divide different clusters and subsequent layers can form categories based on a single cluster or a combination of clusters. 10

[0202] In some implementations, an AI model includes two or more layers of inference. The first layer acts as a logistic classifier which can divide different concentrations of values into separate clusters, while the second layer combines some of these clusters together to create a category for a distinct region. Additionally, subsequent layers can help in extending the distinct regions over more than two categories of clusters. For example, a fully connected AI 15 model may include an input layer corresponding to the number of features tracked, a middle layer corresponding to the number of effective clusters (through iterating between choices), and a final layer corresponding to different regions. Where complete channel response information is input to the AI model, the first layer may act as a shape filter that can correlate certain shapes. Thus, the first layer may lock to a certain shape, the second layer may generate 20 a measure of variation happening in those shapes, and third and subsequent layers may create a combination of those variations and map them to different regions within the space. The output of different layers may then be combined through a fusing layer. B. WLAN sensing system example methods and apparatus

[0203] Section B describes systems and methods that are useful for a wireless sensing 25 system configurated to establish a Wi-Fi sensing network and make sensing measurements.

[0204] FIG.5 depicts an implementation of some of an architecture of a system 500 to form a Wi-Fi sensing network, according to some embodiments.

[0205] System 500 may include a plurality of client devices. The plurality of client devices may include client device 502 and additional client devices 504-(1-N). In an embodiment, the 30 plurality of client devices are associated with an Extended Service Set (ESS). The ESS may be a collection of STAs which include more than one AP device and form a single, logical service set called the ESS. The ESS may include more than one Basic Service Sets (BSSs) and may be identified logically by a Service Set Identifier (SSID) which describes the overall wireless[08 Acording to an dvice 5may i plened ain1.suchdevice5device 502client devicesclient10502may beofbydevices(1-M). Inbe15 to the20

[0209] In an embodiment, client device 502 may be an STA. In some embodiments, clientdevice 502 may be a non-AP STA. client device 502

[0210] Referring again to FIG.5, in some embodiments, additional client devices 504-(1-N) may configured to send one or more sensing transmissions to client device 502 based onwhich one or more sensing measurements may be performed for WLAN sensing. In an embodiment, one or more of additional client devices 504-(1-N) may be a STA, a non-AP STA,30 or a combination thereof. In an embodiment, one or more of additional client devices 504-(1- N) may take a role of sensing initiator and / or sensing responder.

[0211] According to an implementation, one or more of additional client devices 504-(1- N) may be implemented by a device, such as wireless communication device 102 shown in FIG.1. In some implementations, one or more of additional client devices 504-(1-N) may beimplemented by a device, such as wireless communication device 204 shown in FIG.2A and FIG.2B. Further, one or more of additional client devices 504-(1-N) may be implemented by a device, such as wireless communication device 402 shown in FIG.4A and FIG.4B. In some embodiments, any of additional client devices 504-(1-N) may be any computing device, such 5 as a desktop computer, a laptop, a tablet computer, a mobile device, a PDA, or any other computing device. In some implementations, communication between client device 502, one or more of additional client devices 504-(1-N), and AP devices 506-(1-M) may happen via station management entity (SME) and MAC layer management entity (MLME) protocols.

[0212] In some embodiments, AP devices 506-(1-M) may be configured to facilitate the 10 process of WLAN sensing, as explained in further paragraphs using FIG.6 to FIG.23. For example, AP devices 506-(1-M) may provide the information associated with additional client devices 504-(1-N) to client device 502 to facilitate the process of WLAN sensing. Accordingly, client device 502 may perform WLAN sensing based on the received information associated with additional client devices 504-(1-N). According to some implementations, AP devices 506- 15 (1-M) may or may not include / execute a sensing algorithm. In an embodiment, remote processing device (also referred as the AP devices 506-(1-M)) may be a STA. According to an implementation, AP devices 506-(1-M) may be implemented by a device, such as wireless communication device 102 shown in FIG.1. In some implementations, AP devices 506-(1-M) may be implemented by a device, such as wireless communication device 204 shown in FIG. 20 2A and FIG.2B. Further, AP devices 506-(1-M) may be implemented by a device, such as wireless communication device 402 shown in FIG.4A and FIG.4B. In some embodiments, any of AP devices 506-(1-M) may be a hardware device that allows wireless devices to connect to a wired network using Wi-Fi. In example, AP devices 506-(1-M) may be a wireless router, a wireless range extender, WAPs, an outdoor access points, and the like. In embodiments, AP 25 devices 506-(1-M) may fail to support IEEE P802.11bf. In other embodiments, AP devices 506-(1-M) may not be capable of acting as a sensing controller which can manage sensing measurement sessions and a sensing algorithm. Accordingly, client device 502 may take role of sensing initiator where a sensing algorithm determines a WLAN sensing session and the sensing measurements required to fulfill the measurement campaign. In an example, client 30 device 502 may communicate sensing measurement parameters and / or transmission parameters required to initiate a WLAN sensing session to additional client devices 504-(1-N) to coordinate and control sensing transmissions for performing sensing measurements.

[0213] Referring to FIG.5 in more detail, client device 502 may include processor 508 and memory 514. For example, processor 508 and memory 514 of client device 502 may beprocessor 114 and memory 116, respectively, as shown in FIG.1. In an embodiment, client device 502 may further include transmitting antenna(s) 516, receiving antenna(s) 518, and sensing agent 520. In an embodiment, sensing agent 520 may be a module which allows client device to participate in the WLAN sensing. Client device 502 which implements sensing agent 5 520, may implement techniques and technology defined by IEEE P802.11bf which is a standard that describes enhancements to a WLAN MAC and PHY layer for the WLAN sensing. In some embodiments, an antenna may be used to both transmit and receive signals in a half-duplex format. When the antenna is transmitting, it may be referred to as transmitting antenna 516, and when the antenna is receiving, it may be referred to as receiving antenna 518. It is 10 understood by a person of normal skill in the art that the same antenna may be transmitting antenna 516 in some instances and receiving antenna 518 in other instances. In the case of an antenna array, one or more antenna elements may be used to transmit or receive a signal, for example, in a beamforming environment. In some examples, a group of antenna elements used to transmit a composite signal may be referred to as transmitting antenna 516, and a group of 15 antenna elements used to receive a composite signal may be referred to as receiving antenna 518. In some examples, each antenna is equipped with its own transmission and receive paths, which may be alternately switched to connect to the antenna depending on whether the antenna is operating as transmitting antenna 516 or receiving antenna 518.

[0214] In an implementation, sensing agent 520 may be responsible for causing client 20 device 502 to receive sensing transmissions and associated sensing measurement parameters and / or transmission parameters, to calculate sensing measurements. In examples, sensing agent 520 may be responsible for processing sensing measurements to fulfill a sensing goal. In some implementations, receiving sensing transmissions and optionally associated sensing measurement parameters and / or transmission parameters, and calculating sensing 25 measurements may be carried out by sensing agent 520 running in the medium access control (MAC) layer of client device 502 and processing sensing measurements to fulfill a sensing goal may be carried out by an algorithm running in the application layer of client device 502, for example sensing application 522. In examples, a sensing application 522 running in the application layer of client device 502 may be known as a WLAN sensing agent, a sensing 30 application, or sensing algorithm. In examples, sensing application 522 may include and / or execute sensing agent 520. According to some implementations, sensing agent 520 may include and / or execute sensing application 522. In some implementations, sensing agent 520 running in the MAC layer of client device 502 and sensing application 522 running in the application layer of client device 502 may run separately on processor 508. In an implementation, sensingagent 520 may pass one or more of sensing measurement parameters, transmission parameters, or physical layer parameters (e.g., such as channel representation information, examples of which are CSI, CIR, and TD-CRI) between the MAC layer of client device 502 and the application layer of client device 502. In an example, sensing agent 520 in the MAC layer or 5 sensing application 522 in the application layer may operate on physical layer parameters, for example to detect one or more features of interest. In examples, sensing application 522 may form services or features, which may be presented to an end-user. According to an implementation, communication between the MAC layer of client device 502 and other layers or components of client device 502 (including the application layer) may take place based on 10 communication interfaces, such as an MLME interface and a data interface. In examples, sensing agent 520 may be configured to determine a number or timing or an amplitude or a phase of sensing transmissions and sensing measurements for the purpose of WLAN sensing. In some implementations, sensing agent 520 may be configured to transmit sensing measurements to additional client devices 504-(1-N) and / or remote processing device (or the 15 AP devices 506-(1-M)) for further processing. In an implementation, sensing agent 520 may be configured to cause at least one transmitting antenna of transmitting antenna(s) 516 to transmit messages to one or more of additional client devices 504-(1-N) and / or to AP devices 506-(1-M). Further, sensing agent 520 may be configured to receive, via at least one receiving antenna of receiving antenna(s) 518, messages from one or more of additional client devices 20 504-(1-N) or from AP devices 506-(1-M). In an example, sensing agent 520 may be configured to make sensing measurements based on sensing transmissions received from one or more of additional client devices 504-(1-N) and / or AP.

[0215] In some embodiments, client device 502 may include sensing measurements storage 524. In an implementation, sensing measurements storage 524 may store sensing 25 measurements computed by client device 502 based on received sensing transmissions or sensing measurements received by client device 502 based on received messages. In an example, sensing measurements stored in sensing measurements storage 524 may be periodically or dynamically updated as required. In some embodiments, client device 502 may include sensing measurement parameters storage 526. In an implementation, sensing 30 measurement parameters storage 526 may store sensing measurement parameters and / or transmission parameters applicable to one or more sensing measurement setups. In an implementation, sensing measurement parameters storage 526 may store sensing measurement parameters and / or transmission parameters applicable to one or more sensing measurementsessions. In an implementation, sensing measurement parameters storage 526 may store sensing measurement parameters and / or transmission parameters applicable to one or more sensing measurement exchanges. In an example, sensing measurement parameters and / or transmission parameters stored in sensing measurement parameters storage 526 may be 5 periodically or dynamically updated as required. In an implementation, sensing measurements storage 524 and sensing measurement parameters storage 526 may include any type or form of storage, such as a database or a file system or coupled to memory 514.

[0216] In an embodiment, client device 502 may include sensing pulse packet storage 528. In an example, sensing pulse packet storage 528 may store sensing pulse packets received from 10 the plurality of client devices in the ESS including the information collected in the associated mode by client device 502. In an embodiment, a sensing pulse packet may be a packet sent from client device 502 to its associated AP device to indicate the client device capability and status for sensing. Further, client device 502 may also include AP information storage 530. In an example, AP information storage 530 may store information associated with multiple AP 15 devices in the ESS, such as Service Set identifier (SSID) of every AP device whose Beacon frame may be received by client device, frequency channel associated with multiple AP devices, bandwidth of the frequency channel associated with multiple AP devices, and the like. Details on information stored in sensing pulse packet storage 528 and AP information storage 530 have been explained in further paragraphs using FIG 17. 20

[0217] Referring again to FIG.5, additional client device 504-1 (which is an example of one or more of additional client devices 504-(1-N)) may include processor 532-1 and memory 526-1. For example, processor 532-1 and memory 534-1 of additional client device 504-1 may be processor 114 and memory 116, respectively, as shown in FIG. 1. In an embodiment, additional client device 504-1 may further include transmitting antenna(s) 536-1, receiving 25 antenna(s) 538-1, and sensing agent 540-1.

[0218] Sensing agent 540-1 may be configured to cause at least one transmitting antenna of transmitting antenna(s) 536-1 and at least one receiving antenna of receiving antenna(s) 538- 1 to exchange messages with client device 502 or with AP devices 506-(1-M). In some embodiments, an antenna may be used to both transmit and receive in a half-duplex format. 30 When the antenna is transmitting, it may be referred to as transmitting antenna 536-1, and when the antenna is receiving, it may be referred to as receiving antenna 538-1. It is understood by a person of normal skill in the art that the same antenna may be transmitting antenna 536-1 in some instances and receiving antenna 538-1 in other instances. In the case of an antenna array,one or more antenna elements may be used to transmit or receive a signal, for example, in a beamforming environment. In some examples, a group of antenna elements used to transmit a composite signal may be referred to as transmitting antenna 536-1, and a group of antenna elements used to receive a composite signal may be referred to as receiving antenna 538-1. In 5 some examples, each antenna is equipped with its own transmission and receive paths, which may be alternately switched to connect to the antenna depending on whether the antenna is operating as transmitting antenna 536-1 or receiving antenna 538-1.

[0219] In an implementation, sensing agent 540-1 may be responsible for causing additional client device 504-1 to send sensing transmissions and, in examples, receive 10 associated sensing measurements from client device 502 and / or AP devices 506-(1-M). In examples, sensing agent 540-1 may be responsible for processing sensing measurements to fulfill a sensing goal. In some implementations, sensing agent 540-1 may run in the medium access control (MAC) layer of additional client device 504-1 and processing sensing measurements to fulfill a sensing goal may be carried out by sensing application 542-1, which 15 in examples may run in the application layer of additional client device 504-1. In examples, sensing application 542-1 running in the application layer of additional client device 504-1 may be known as a WLAN sensing agent, a sensing application, or a sensing algorithm. In examples, sensing application 542-1 may include and / or execute sensing agent 540-1. According to some implementations, sensing agent 540-1 may include and / or execute sensing application 542-1. 20 In some implementations, sensing agent 540-1 may run in the MAC layer of additional client device 504-1 and sensing application 542-1 may run in the application layer of additional client device 504-1. In some implementations, sensing agent 540-1 of additional client device 504-1 and sensing application 542-1 may run separately on processor 532-1. In an implementation, sensing agent 540-1 may pass sensing measurement parameters, transmission parameters, or 25 physical layer parameters between the MAC layer of additional client device 504-1 and the application layer of additional client device 504-1. In an example, sensing agent 540-1 in the MAC layer or sensing application 542-1 in the application layer may control physical layer parameters, for example physical layer parameters used to generate one or more sensing transmissions. In examples, sensing application 542-1 may form services or features, which 30 may be presented to an end-user. According to an implementation, communication between the MAC layer of additional client device 504-1 and other layers or components of additional client device 504-1 (including the application layer) may take place based on communication interfaces, such as an MLME interface and a data interface. In examples, sensing agent 540-1 may be configured to determine a number or timing or an amplitude or a phase of sensingtransmissions for the purpose of WLAN sensing. In some implementations, sensing agent 540- 1 may be configured to cause additional client device 504-1 to transmit sensing transmissions to client device 502 and / or AP devices 506-(1-M). In an implementation, sensing agent 540-1 may be configured to cause at least one transmitting antenna of transmitting antenna(s) 536-1 5 to transmit messages to client device 502 or to AP devices 506-(1-M). Further, sensing agent 540-1 may be configured to receive, via at least one receiving antenna of receiving antenna(s) 538-1, messages from client device 502 or from AP devices 506-(1-M).

[0220] In some embodiments, additional client device 504-1 may include sensing measurements storage 546-1. In an implementation, sensing measurements storage 546-1 may 10 store sensing measurements computed by additional client device 504-1 or received in a message by additional client device 504-1. In an implementation, sensing measurements storage 546-1 may store sensing measurements computed by client device 502 based on sensing transmissions sent by additional client device 504-1 and sent by client device 502 to additional client device 504-1. In an example, sensing measurements stored in sensing measurements 15 storage 546-1 may be periodically or dynamically updated as required. In an implementation, sensing measurements storage 546-1 may include any type or form of storage, such as a database or a file system or coupled to memory 534-1.

[0221] In some embodiments, additional client device 504-1 may include sensing measurement parameters storage 548-1. In an implementation, sensing measurement 20 parameters storage 548-1 may store sensing measurement parameters and / or transmission parameters applicable to one or more sensing measurement sessions. In an implementation, sensing measurement parameters storage 548-1 may store sensing measurement parameters and / or transmission parameters applicable to one or more sensing measurement setups. In an implementation, sensing measurement parameters storage 548-1 may store sensing 25 measurement parameters and / or transmission parameters applicable to one or more sensing measurement exchanges. In an example, sensing measurement parameters and / or transmission parameters stored in sensing measurement parameters storage 548-1 may be periodically or dynamically updated as required. In an implementation, sensing measurements storage 548-1 and sensing measurement parameters storage 548-1 may include any type or form of storage, 30 such as a database or a file system or coupled to memory 534-1.

[0222] In an embodiment, additional client device 504-1 may include sensing pulse packet storage 550-1. In an example, sensing pulse packet storage 550-1 may store sensing pulse packets received from the plurality of client devices in the ESS including the informationcollected in the associated mode by client device 502. Further, additional client device 504-1 may also include AP information storage 552-1. In an example, AP information storage 552-1 may store information associated with multiple AP devices in the ESS, such as Service Set identifier (SSID) of every AP device whose Beacon frame may be received by client device 5 502, frequency channel associated with multiple AP devices, bandwidth of the frequency channel associated with multiple AP devices, and the like. Details on information stored in sensing pulse packet storage 550-1 and AP information storage 552-1 have been explained in further paragraphs using FIG 17.

[0223] Referring to FIG.5 in more detail, AP device 506-1 (which is an example of one 10 or more of AP devices 506-(1-M)) may include processor 554-1 and memory 556-1. For example, processor 554-1 and memory 556-1 of AP device 506-1 may be processor 114 and memory 116, respectively, as shown in FIG.1. In an embodiment, AP device 506-1 may further include transmitting antenna(s) 558-1 and receiving antenna(s) 560-1. In some embodiments, an antenna may be used to both transmit and receive signals in a half-duplex format. When the 15 antenna is transmitting, it may be referred to as transmitting antenna 558-1, and when the antenna is receiving, it may be referred to as receiving antenna 560-1. It is understood by a person of normal skill in the art that the same antenna may be transmitting antenna 558-1 in some instances and receiving antenna 560-1 in other instances. In the case of an antenna array, one or more antenna elements may be used to transmit or receive a signal, for example, in a 20 beamforming environment. In some examples, a group of antenna elements used to transmit a composite signal may be referred to as transmitting antenna 558-1, and a group of antenna elements used to receive a composite signal may be referred to as receiving antenna 560-1. In some examples, each antenna is equipped with its own transmission and receive paths, which may be alternately switched to connect to the antenna depending on whether the antenna is 25 operating as transmitting antenna 558-1 or receiving antenna 560-1. Further, AP device 506-1 may include sensing pulse packet storage 564-1. In an embodiment, sensing pulse packet storage 564-1 may include any type or form of storage, such as a database or a file system or coupled to memory 556-1. Sensing pulse packet storage 564-1 may store sensing pulse packets received from the plurality of client devices in the ESS. 30

[0224] In an embodiment, AP device 506-1 may include a sensing agent and / or a sensing application (not shown). In an implementation, the sensing agent may be responsible for determining sensing measurement parameters and / or transmission parameters for one or more sensing measurement setups. In examples, the sensing agent may receive sensing measurement parameters and / or transmission parameters for one or more sensing measurement setups fromthe sensing algorithm. In an example, the sensing agent may receive sensing measurements from one or more of plurality of client devices 502, 504-(1-N) and may process the sensing measurements to fulfill a sensing goal. In an example, the sensing agent may receive channel representation information (such as CSI or TD-CRI) from client device 502 and additional 5 client device 504-(1-N) to process the channel representation information for fulfilling a sensing goal. In some implementations, the sensing agent may receive sensing measurements or channel representation information and may provide the received sensing measurements or channel representation information to the sensing algorithm (or sensing application), and the sensing algorithm may receive the sensing measurements or channel representation 10 information from the sensing agent and may process the information to fulfill a sensing goal. In other implementations, AP device 506-1 may fail to perform the functionalities / task associated with the sensing agent due to one or more errors.

[0225] In an embodiment, AP device 506-1 may include network coordination application 562-1. Further, network coordination application 562-1 may be installed in one of the AP of 15 the ESS. Network coordination application 562-1 may facilitate connection of every AP with a network coordinator via the logical links. Furthermore, network coordination application 562- 1 may facilitate coordination of APs and plurality of client devices, collection of the of plurality of client devices via every AP in the ESS and share this information and the AP may this to every device in the ESS. 20 andevice 502amay perform areceived by(1-N)sensing502 acta25is FIG.5.asaafor the same sensingFurther, each of the plurality of client devices may use the systems and methods of present disclosure to form the sensing network.30cl nliet47[ ording too mooni netr ma5be byIEEE rd inc e IEIEEE 802. IEEEI82.fu raifieardan ongoing maintenance update to the IEEE 802.11 standard and IEEE 802.11be defines the next generation of standard. IEEE 802.11az is an extension of 10 the IEEE 802.11 and IEEE 802.11ax standards which adds new functionality. In some implementations, communications may be governed by other standards (other or additional IEEE standards or other types of standards). etwork 566which are not required by system 500 to be governed bymay be implemented by an instance of any type of15 . Further, IEEE 802.11ax includes Orthogonal FrequencyDivision Multiple Access (OFDMA), which allows client device 502 to simultaneouslytransmit data to all participating devices, such as additional client devices 504-(1-N), and viceversa using a single transmission opportunity (TXOP). The efficiency of OFDMA depends on how client device 502 schedules channel resources (interchangeably referred to as RUs) among 20 additional client devices 504-(1-N) and configures transmission parameters. According to an implementation, system 500 may be an OFDMA enabled system.

[0231] In a Wi-Fi system, both data transmission and sensing transmission may happen at different TXOPs. The Wi-Fi sensing system may utilize a TXOP that is not used for data transmissions for Wi-Fi sensing. The TXOP used for data transmissions may be named as the 25 data TXOP, while the TXOP used for sensing transmissions may be named as the sensing TXOP.

[0232] Referring back to FIG.5, according to one or more implementations, WLAN sensing system 500 may participate in a sensing session. In examples, a sensing session is an agreement between a sensing initiator and a sensing responder to participate in a WLAN 30 sensing procedure (also known as Wi-Fi sensing procedure.) In examples, sensing measurement parameters associated with a sensing session may be determined by a sensing initiator and may be exchanged between the sensing initiator and a sensing responder. In examples, sensing initiator may be client device 502 and sensing responder(s) may be one (ormore) of additional client devices 504-(1-N). In examples, sensing initiator may be client device 502 and sensing responder may be additional client device 504-1. In examples, sensing initiator may be additional client device 504-1, and sensing responder may be client device 502. In examples, a networking device (e.g. client device 502, additional client device 504-1 or AP 5 device 506-1) may participate in multiple sensing sessions either as a sensing initiator or as a sensing responder. In examples, client device 502 may participate in multiple sensing sessions either as a sensing initiator or as a sensing responder. In examples, AP device 506-1 may or may not participate in multiple sensing sessions as a sensing initiator or as a sensing responder.

[0233] FIG.6 is reproduced from IEEE P802.11bf D3.0, Figure AD-1 and illustrates an 10 example of WLAN sensing procedure 600 (also known as Wi-Fi sensing procedure 600) according to some embodiments. In examples, WLAN sensing procedure 600 allows a STA to perform WLAN sensing. In an example, WLAN sensing procedure 600 enables a STA to obtain one or more sensing measurements of the wireless transmission channel between two or more STAs and or the wireless transmission channel between a receive antenna and a transmit 15 antenna of a STA. In examples, WLAN sensing procedure 600 is composed of one or more of a sensing session setup, a sensing measurement setup, one or more sensing measurement exchanges, sensing measurement setup termination, and sensing session termination.

[0234] FIG.6 illustrates an example of WLAN sensing procedure 600 with a sensing measurement session setup with a STA with MAC ADDR=A and Association Identifier 20 (AID)=1 and is a reproduction of Figure AD-1 of IEEE P802.11bf D3.0. In examples, a sensing measurement session setup establishes a sensing session or a sensing procedure. In examples, the sensing measurement session may be identified by the AID of the STA involved in the sensing measurement session. FIG.6 illustrates a measurement session setup procedure for the STA with MAC ADDR=A, where the measurement session ID = 1. 25

[0235] In examples, a sensing measurement session setup allows for a sensing initiator and a sensing responder to exchange and agree on operational attributes associated with a sensing measurement exchange. A sensing initiator may transmit a Sensing Measurement Setup Request frame to a sensing responder with which it intends to perform a sensing measurement session setup. An example of a Sensing Measurement Request frame Action field format 702 30 (which may also be referred to as a Sensing Measurement Setup Request frame Action field format) as described by IEEE P802.11bf D3.0 in Figure 9-1198a is provided in FIG.7A. As shown in the example illustrated in FIG.7A, in embodiments, a Sensing Measurement Setup Request frame Action field format may include one or more of a Category field, a Public Action field, a Dialog Token field, a Sensing Comeback Info field, a Measurement Session IDIndication field, and a Sensing Measurement Parameters element. In examples, a Category value code is defined for a “Protected Sensing Frame.” In an embodiment, a Protected Sensing Action field is defined in the octet immediately after the Category field in order to differentiate Protected Sensing Frame formats from Public Sensing Frame formats. 5

[0236] FIG.7B is reproduced from IEEE P802.11bf D3.0 Figure 9-1001bc and illustrates an example, according to some embodiments, of a Sensing Measurement Parameters element format 704. In examples, a Sensing Measurement Parameters element indicates operational attributes of a corresponding sensing measurement exchange. In examples, the Sensing Measurement Parameters element comprises a Sensing Measurement Parameters field and a 10 Sensing subelements field. FIG.7C is reproduced from IEEE P802.11bf D3.0 Figure 9-1001bd and illustrates an example of a format of a Sensing Measurement Parameters field format, according to some embodiments. In an example, a Sensing Measurement Parameters field comprises a Sensing Transmitter subfield. The Sensing Transmitter subfield may be set to 1 to indicate a sensing responder assumes a sensing transmitter role, such as additional client device 15 504-1. In an example the sensing responder assumes a sensing transmitter role according to the Sensing Transmitter subfield for the Sensing Measurement Session ID Indication associated with the Sensing Measurement Parameters field. In an example, the Sensing Measurement Parameters field comprises a Sensing Receiver subfield. The Sensing Receiver subfield may be set to 1 to indicate a sensing responder assumes a sensing receiver role, such as client device 20 502-1. In an example the sensing responder assumes a sensing receiver role according to the Sensing Receiver subfield for the Sensing Measurement Session ID Indication associated with the Sensing Measurement Parameters field.

[0237] Referring again to FIG.7C, in examples, a Sensing Measurement Parameters field format 706 includes a Sensing Measurement Report Requested subfield if the Sensing Receiver 25 subfield indicates that the sensing responder should assume a sensing receiver role. In an example, the Sensing Measurement Report Requested subfield may indicate that whether or not a sensing responder sends Sensing Measurement Report frames in sensing measurement exchanges that result from the sensing measurement session setup.

[0238] In examples, after the sensing responder receives the Sensing Measurement Setup 30 Request frame, the sensing responder may transmit a Sensing Measurement Setup Response frame. An example of a Sensing Measurement Response frame Action field format 708 (which may also be referred to as a Sensing Measurement Setup Response frame Action field format) is described by IEEE P802.11bf D3.0 Figure 9-1198d and provided in FIG.7D. In examples, the sensing responder may use a Status Code field in the Sensing Measurement Setup Responseframe to indicate whether the sensing responder accepts the requested sensing measurement setup parameters in the received Sensing Measurement Setup Request frame. In an embodiment, the Status Code field may be set to 0 indicating a successful sensing measurement setup, where the sensing responder accepts the operational attributes included in the Sensing 5 Measurement Setup Request frame. In examples, the sensing responder may indicate in the Sensing Measurement Setup Response frame that the operational attributes included in the Sensing Measurement Setup Request frame sent by the sensing initiator are not accepted, for example by setting a Status Code field to a non-zero value. In examples, the sensing responder may indicate in the Sensing Measurement Setup Response frame suggested sensing 10 measurement parameters, for example to indicate to the sensing initiator one or more operational attributes preferred by the sensing responder. In examples, the sensing responder may indicate to the sensing initiator that suggested sensing measurement parameters are included in the Sensing Measurement Setup Response frame by setting a Status Code field to a non-zero value. 15

[0239] In examples, the sensing initiator may assign a role to the sensing responder as part of the sensing measurement setup sent in the Sensing Measurement Setup Request frame. For example, the sensing initiator may indicate to a sensing responder that the sensing responder is to assume the role of a sensing receiver, such as client device 502, or the role of a sensing transmitter, such as additional client device 504-1, or the role of sensing receiver and sensing 20 transmitter. In examples, sensing initiator may indicate to sensing responder whether the sensing responder sends sensing measurement report frames in sensing measurement exchanges. In an embodiment, the role assigned to the sensing responder and / or whether the sensing responder sends sensing measurement report frames persists until the sensing measurement setup is terminated. 25

[0240] Referring again to FIG.6 and the measurement session with the STA with MAC ADDR=A identified by the STA AID, AID=1, the measurement session setup is followed by one or more sensing measurement exchanges and measurement reporting instances which may be performed based on the defined operational attribute set. In the example shown in FIG.6, the one or more sensing measurement exchanges and measurement reporting instances for the 30 STA with MAC ADDR=A may be assigned measurement exchange IDs, for example a first measurement exchange may be assigned measurement exchange ID=1, and a second measurement exchange may be assigned measurement exchange ID=2. In examples, a measurement exchange may be uniquely associated with a measurement session setup.

[0241] Referring again to FIG.6, a second measurement session setup may be initiated for the STA with MAC ADDR=A, which may be identified as measurement session ID=2. Measurement session ID=2 may be associated with a second operational attribute set. In examples, after the second sensing measurement session setup, any subsequent one or more 5 sensing measurement exchanges may be performed based on either the first operational attribute set (measurement session ID=1) or the second operational attribute set (measurement session ID=2.)

[0242] Referring again to FIG.6, a measurement session setup with a STA with MAC ADDR=B and Unassociated Station Identifier (USID)=2. In examples, the measurement 10 session may be identified by the USID of the STA with MAC ADDR=B. FIG. 6 further illustrates a sensing measurement exchange for the STA with MAC ADDR=B. In the example, the operational attribute set for the measurement session for the STA with MAC ADDR=B is the same as the second operational attribute set established with the STA with MAC ADDR=A, and the same measurement session ID is used for both the STA with MAC ADDR=A and the 15 STA with MAC ADDR=B. That is, a sensing measurement session ID (which may also be referred to as a sensing measurement session label) may apply to one or more STAs. In examples according to FIG.6, subsequent sensing measurement exchanges associated with measurement session ID=2 may be associated with the STA with MAC ADDR=A, the STA with MAC ADDR=B, or with both the STA with MAC ADDR=A and the STA with MAC 20 ADDR=B. Each sensing measurement exchange may have one-to-many (including one-to-one) announcement and / or triggering and may have either one-to-many or many-to-one (including one-to-one) sounding.

[0243] In examples, an operational attribute set of a measurement session may be terminated by performing a sensing measurement session termination procedure, for example 25 as is shown in FIG. 6 for sensing measurement session ID=1 and the STA with MAC ADDR=A. In examples, the sensing measurement session ID of a terminated sensing measurement setup may be used for a subsequent sensing measurement session. This is shown in FIG.6 where a sensing measurement session with ID=1 is established for the STA with MAC ADDR=B, after the termination of the sensing measurement session ID=1 with the STA 30 with MAC ADDR=A. In some embodiments, a sensing measurement session may be terminated using a sensing measurement session termination procedure, as shown in FIG.6.

[0244] FIG.8A illustrates that measurement exchanges 802 between a sensing initiator and a sensing responder may be one-to-many or many-to-one. In examples, a measurement exchange and / or measurement reporting may have a one-to-one (single device to single device)announcement or triggering or may have a one-to-many (single device to multiple devices) announcement or triggering. In examples, a measurement exchange may have one-to-one, one- to-many, or many-to-one (many devices to a single device) sounding.

[0245] As previously described, a sensing session is an agreement between a sensing 5 initiator and a sensing responder to participate in a WLAN (Wi-Fi) sensing procedure. In examples, a sensing session is pairwise and in examples, may be identified by a sensing measurement ID, MAC addresses of the sensing initiator and the sensing responder, by AID / USID values, or by any combination of these or other identifiers. FIG.8B shows an example of pairwise exchanges or procedures 804 that may take place between a sensing 10 initiator and a sensing responder related to a sensing measurement session, which may include one or more of a sensing session setup, a sensing measurement setup (a sensing measurement session setup), a sensing measurement setup termination (a sensing measurement session termination), and a sensing session termination.

[0246] In examples, a sensing measurement exchange of a WLAN sensing procedure may 15 be a trigger-based (TB) sensing measurement exchange. FIG.9A and FIG.9B depict a message flow 900 of a sensing measurement session of a WLAN sensing procedure comprising a sensing measurement session setup procedure followed by one or more trigger-based (TB) sensing measurement exchanges that consist of either NDPA sounding or trigger frame (TF) sounding, followed by a sensing measurement session termination procedure, according to 20 some examples. In examples, a TB sensing measurement exchange may be used where the sensing initiator is an AP, and one or more non-AP STAs are sensing responders. In examples, a TB sensing measurement exchange may include a polling phase, an NDPA sounding phase, a trigger frame (TF) sounding phase, and a reporting phase.

[0247] FIG.10A is reproduced from IEEE P802.11bf D3.0 Figure 11-102b and illustrates 25 an example of TB sensing measurement exchange 1002 including a polling phase, an NDPA sounding phase, a Trigger frame (TF) sounding phase, and a reporting phase. In some examples, TB sensing measurement exchange 1002 may be preceded by an initial Control frame (ICF). The ICF may be sent by a sensing initiator prior to the polling phase. In an example, the sensing initiator may be an AP affiliated with an AP MLD. In an example, the 30 ICF may provide control information to a sensing responder. The control information may relate to multi-link operation (MLO), to the sensing initiator, and / or to the sensing responder.

[0248] The table in FIG.10B indicates valid combinations of phases 1004 of a TB sensing measurement exchange, in some examples.

[0249] FIG.11 is reproduced from IEEE P802.11bf D3.0 Figure 11-102c and provides one example of a TB sensing measurement exchange 1100 with client device 502, additional client devices 504-(1-N)), AP device 506-1, or any combination thereof in the role of a sensing initiator and six STAs, referred to as STA 1, STA 2, STA 3, STA 4, STA 5 and STA 6 (such 5 as client devices 502 and additional client devices 504-(1-N)), as discussed with reference to FIG.5), all of which in the example are sensing responders. In example, the client device (for example, any one of STA 4, STA 5 and STA 6) communicates with the sensing initiator to achieve the sensing goal. In the example, the TB sensing measurement exchange comprises a polling phase, an NDPA sounding phase, a TF sounding phase, and a reporting phase. In the 10 example, STA 1, STA 2 and STA 3 are acting as sensing transmitters, such as additional client device 504-1, additional client device 504-2 and additional client device 504-3. In the example of FIG.11, STA 4, STA 5, and STA 6 are acting as sensing receivers, such as client device 502. In examples, in the polling phase, the AP acting as the sensing initiator transmits a Sensing Polling Trigger frame to STA 1, STA 2, STA 3, STA 4, STA 5, and STA 6. In an embodiment, 15 sensing transmitter STA 1 and sensing transmitter STA 2 respond to the Sensing Polling Trigger frame with an indication that the STA is available to participate in a sensing measurement exchange. In examples, the indication is a CTS-to-self frame. In the example, sensing transmitter STA 3 does not respond to the Sensing Polling Trigger frame sent by the sensing initiator, indicating that STA 3 will not participate in the sensing measurement 20 exchange. In an embodiment, sensing receiver STA 4 and sensing receiver STA 5 respond to the Sensing Polling Trigger frame with an indication that the STA is available to participate in a sensing measurement exchange. In examples, the indication is a CTS-to-self frame. In the example, sensing receiver STA 6 does not respond to the Sensing Polling Trigger frame sent by the AP as the sensing initiator, indicating that STA 6 will not participate in the sensing 25 measurement exchange.

[0250] Referring again to FIG.11, in a NDPA sounding phase, the AP acting as sensing initiator assumes the role of sensing transmitter. In examples, the AP as sensing transmitter transmits a sensing transmission. In examples, the sensing transmission may be a broadcast transmission. In examples, the sensing transmission may be a unicast transmission to one or 30 more STAs, for example to sensing receiver STA 4, sensing receiver STA 5 and / or to sensing receiver STA 6. In examples, a period of one or more SIFSs elapses between the AP as sensing transmitter sending the sensing NDPA frame and when the AP as sensing transmitter sends the one or more sensing transmissions. In examples, one or more of the sensing transmissions may be a full bandwidth NDP frame. In examples, one or more of the sensing transmissions may bea partial bandwidth NDP frame. In examples, one or more of the NDP frames may be an SI2SR NDP frame.

[0251] The sensing measurement exchange of FIG.11 includes a TF Sounding phase. In examples, in the TF Sounding phase, the AP as the sensing initiator sends a Sensing Sounding 5 Trigger frame to sensing transmitter STA 1 and to sensing transmitter STA 2. In examples, responsive to receiving the Sensing SR2SI Sounding Trigger frame, sensing transmitter STA 1 and sensing transmitter STA 2 send sensing transmissions to the AP. In examples, the sensing transmissions may comprise NDP transmissions. In an example, one or more of the NDP transmissions to the AP may be SR2SI NDP transmissions (as shown in the example of FIG. 10 11). In examples, a period of one or more SIFS elapses between sensing transmitter STA 1 receiving the Sensing SR2SI Sounding Trigger frame and transmitting a sensing transmission, and in examples a period of one or more SIFS elapses between sensing transmitter STA 2 receiving the Sensing SR2SI Sounding Trigger frame and transmitting a sensing transmission. In examples, the AP may assume the role of sensing receiver, and the AP may make sensing 15 measurements on the sensing transmissions from sensing transmitter STA 1 and sensing transmitter STA 2.

[0252] In examples, a sensing measurement exchange of a WLAN sensing procedure may be a non-trigger-based (non-TB) sensing measurement exchange. FIG. 12A and FIG. 12B depict message flow 1200 of a sensing measurement session setup procedure followed by one 20 or more non-TB sensing measurement exchanges of a WLAN sensing procedure that consist of one or more of downlink sounding or uplink sounding, according to some embodiments, followed by a sensing measurement session termination procedure, according to some examples. In examples, a non-TB sensing measurement exchange may be used where the sensing initiator is a non-AP STA, and an AP is the sensing responder. In examples of uplink 25 sounding described by IEEE P802.11bf, an example of which is shown in FIG.12A and FIG. 12B, the sensing initiator (non-AP STA) acting as a sensing transmitter (for example, additional client device 504-1) transmits a sensing announcement frame followed by a sensing transmission. In examples, the sensing announcement frame may be an NDPA frame. In examples, the sensing transmission may be an NDP frame (for example, an SI2SR NDP frame). 30 In examples, responsive to receiving the sensing transmission, the AP acting as a sensing receiver (for example, client device 502), may transmit to the sensing initiator (non-AP STA in the role of additional client device 504-1) a sensing measurement report, for example one or more Sensing Measurement Report frames. In examples of downlink sounding as shown in FIG.12A and FIG.12B, the sensing initiator (non-AP STA) acting as a sensing transmits asensing announcement frame. In examples, the sensing announcement frame may be an NDPA frame. In examples, responsive to receiving the sensing announcement frame, the AP acting as sensing transmitter may transmit one or more sensing transmissions. In examples, one or more of the sensing transmissions may be an NDP frame (for example, an SI2SR NDP frame). In 5 examples, the non-AP STA acting as a sensing receiver, responsive to receiving a sensing transmission, may make a sensing measurement on the sensing transmission. In examples, the sensing measurement session may be terminated by the sensing initiator or the sensing responder transmitting a SENS Measurement Setup Termination frame. In examples, the sensing responder or sensing initiator (respectively) may respond with an acknowledgment. 10

[0253] FIG.13 is reproduced from IEEE P802.11bf D3.0 figure 11-102i and illustrates a detailed example of non-TB sensing measurement exchange 1300, according to some embodiments. In examples, STA 1 acting as sensing initiator and sensing transmitter, such as additional client device 504-1, transmits a sensing announcement frame. In examples, the sensing announcement frame may be a sensing NDPA frame. In examples, one or more SIFS 15 may elapse followed by STA 1 acting as sensing initiator and sensing transmitter transmitting one or more sensing transmissions. In examples, one or more of the sensing transmissions may be an NDP frame (for example, a SI2SR NDP frame). In an example. STA 1 acting as sensing initiator and sensing receiver, such as AP which is an example of sensing receiver, may transmit a sensing announcement frame followed after a period by an SI2SR NDP frame. In examples, 20 the sensing announcement frame may be a sensing NDPA frame, and the period may be a SIFS. In examples, one or more SIFS may elapse followed by AP acting as sensing responder and sensing transmitter transmitting one or more sensing transmissions. In examples, AP acting as sensing responder and sensing transmitter does not transmit an NDPA frame and instead transmits a sensing transmission one SIFS after receiving the SI2SR NDP. In examples, the 25 sensing transmission may be an NDP frame (for example, an SR2SI NDP frame).

[0254] FIG.14A is reproduced from IEEE P802.11bf D3.0, Figure 9-1198f and illustrates an example of a Sensing Measurement Report frame Action field format. In some examples, a Sensing Measurement Report frame may be transmitted to provide WLAN sensing measurements, for example to a sensing agent or a sensing algorithm of a sensing initiator. In 30 examples, a Sensing Measurement Report frame may comprise one or more Sensing Measurement Report Containers. FIG.14B is reproduced from IEEE P802.11bf D3.0 Figure 9-189g and is an example of Sensing Measurement Report Container field format 1401. A Sensing Measurement Report Container may comprise a single sensing measurement report, in some embodiments.

[0255] Referring again to FIG. 14B, in embodiments a Sensing Measurement Report Container may include Sensing Measurement Report Control field. In examples, Sensing Measurement Report Control field may contain information necessary to interpret the Sensing Measurement Report field. For example, the Sensing Measurement Report Control field format 5 may comprise one or more subfields. In an embodiment, one or more subfields of Sensing Measurement Report Control field may include PHY layer parameters used by the sensing receiver when performing the sensing measurement, for example receiver antenna beamforming or spatial layer information. In examples, Sensing Measurement Report Control field 1404 definitions are shown in Table 9-127h from IEEE P802.11bf D3.0, which is 10 reproduced in TABLE 1 below.TABLE 1

[0256] In a sensing session, exchanges of transmissions between sensing receiver (i.e., client device 502 or additional client devices 504-(1-N)) and one or more of plurality of sensing transmitters (i.e., additional client devices 504-(1-N) or client device 502) may occur. In an 5 example, control of these transmissions may be with the MAC layer of the IEEE 802.11 stack. According to an implementation, sensing receiver may secure a TXOP which may be allocated to one or more sensing transmissions by one or more of plurality of sensing transmitters. According to an implementation, sensing receiver may allocate channel resources (or RUs) within a TXOP to the one or more of plurality of sensing transmitters. In an example, sensing 10 receiver may allocate the channel resources to the one or more of plurality of sensing transmitters by allocating time and bandwidth within the TXOP to the one or more of plurality of sensing transmitters.

[0257] According to an implementation, example 1500 of a hierarchy of fields within sensing trigger message is shown in FIG.15A to FIG.15I. 15

[0258] As described in FIG.15A and based upon a Trigger frame as described by IEEE P802.11, the Common Info field may contain information which is common to one or more of a plurality of sensing transmitters (e.g., additional client devices 504-(1-N), as shown in FIG. 5). According to some implementations, the requirement of an NDPA preceding an NDP maybe optional. This may be indicated to one or more of the plurality of sensing transmitters and may, for example be encoded into a “Trigger Dependent Common Info” field if the requirement is common the plurality of sensing transmitters, or into a “Trigger Dependent User Info” field if the requirement is specific to one or more sensing transmitters of the plurality of sensing 5 transmitters. According to an example, the requirement for a sensing announcement (for example, an NDPA) preceding a sensing response NDP may be encoded by a single bit where 0 (bit clear) indicates that a sensing announcement is optional and 1 (bit set) indicates that a sensing announcement is required.

[0259] As described by FIG.15B which is a reproduction of IEEE P802.11bf D3.0 Figure 10 9-102a (Trigger Dependent Common Info field format of the Sensing Polling, SR2SI Sounding, Sensing Reporting, and Sensing Threshold-based Reporting Trigger frame), a Trigger Dependent Common Info field format may include the Sensing Trigger Subtype field with different values to indicate different Sensing Trigger frame variants. The Sensing Trigger frame variants may be used for Sensing Polling, SR2SI Sounding, Sensing Threshold-based 15 Report, Sensing Reporting, or SR2SR Sounding.

[0260] As adapted from IEEE P802.11 and IEEE P802.11bf and described in FIG.15C, a Trigger Type (within B0..3 of “Common Info” field) may be defined which represents a sensing trigger message. In examples, a sensing Trigger message may have a Trigger Type subfield value of 8. 20

[0261] As described by IEEE P802.11 and reproduced in FIG.15D the sensing trigger message may have an uplink bandwidth (UL BW) subfield value of 0, 1, 2 or 3 corresponding to bandwidths of 20 MHz, 40 MHz, 80 MHz, or 80+80 MHz (160 MHz).

[0262] As described in FIG.15E and based upon a Trigger frame as described by IEEE P802.11, the User Info List contains information which is specific to each of the plurality of 25 sensing transmitters. In examples, the User Info List may include the AID of a sensing transmitter, an RU allocation for a sensing transmitter, and other Trigger Dependent User Info.

[0263] As described in FIG. 15F and leveraging the definition of IEEE P802.11, the AID12 subfield of the User Info List illustrated in FIG.15D may be used to address a specific sensing transmitter of the plurality of sensing transmitters. 30

[0264] As described in FIG.15G and FIG.15H and leveraging the definition of IEEE P802.11, an RU Allocation subfield is used to allocate resource units (RU) to each of the plurality of sensing transmitters.

[0265] As described in FIG.15I, the Trigger Dependent User Info subfield may be used to request the transmission configuration and / or steering matrix configuration for one or moresensing transmitters of the plurality of sensing transmitters that the sensing trigger message is triggering. C. Systems and methods to form a sensing network 5

[0266] The present disclosure generally relates to systems and methods to form a sensing network. In particular, the present disclosure relates to systems and methods for establishing a Wi-Fi sensing network carried out by a client device.

[0267] A WLAN sensing system may be configured to detect features of interest in a sensing space. The WLAN sensing system may be a network of Wi-Fi enabled devices which 10 are part of IEEE 802.11 network (sometimes referred to as a Basic Service Set (BSS) or Extended Service Set (ESS)). The features of interest may include motion of objects and motion tracking, presence detection, intrusion detection, gesture recognition, fall detection, breathing rate detection, and other applications. The sensing space refer may refer to any physical space in which the WLAN sensing system may operate and may include a place of abode, a place of 15 work, a shopping mall, a sport, or sports hall or sports stadium, a garden, or any other physical space.

[0268] FIG.16 depicts exemplary Extended Service Set (ESS) 1600 (which is an example of network 566), according to some embodiments. ESS 1600 may include multiple BSS(s). Each BSS may include an AP device, multiple client devices, and a network coordinator. In an 20 embodiment, the multiple client devices may communicate with different APs on different frequency channels. In an example, a client device may be a networking device, non-AP STA, station (STA) or Multi-AP device with a sensing application (also known as sensing agent or sensing algorithm) pre-installed on it. In an embodiment, the multi-AP device may be a device that has Backhaul STA module for backhaul link connection and Fronthaul AP module for 25 fronthaul link connection. In an embodiment, the client device may support multiple frequency channels and may communicate with the AP device for data transmission on a single frequency channel. In an embodiment, the client device may communicate with another client device for sensing transmissions on a different frequency channel. However, the client device may also be a device capable of operating on a single frequency channel at a time. 30

[0269] Referring to FIG.16 in detail, ESS 1600 may include two BSSs i.e., first BSS 1602 and second BSS 1604. First BSS 1602 may include first AP device 1606, first client device 1608 and third client device 1634. Further, second BSS 1604 may include second AP device 1610 and second client device 1612. In an embodiment, first AP device 1606 and second AP device 1610 may communicate with each other via AP data link 1636. In first BSS 1602, firstclient device 1608 may be communicatively coupled with first AP device 1606 via first data link 1614, and third client device 1634 may be communicatively coupled with first AP device 1606 via third data link 1616. In an embodiment, first data link 1614 and third data link 1616 may be on a common frequency channel (e.g., Frequency Channel 11). In second BSS 1604, 5 second client device 1612 may be communicatively coupled with second AP device 1610 via second data link 1618. Further, second data link 1618 may be on a different frequency channel (e.g., Frequency Channel 7) as compared to first data link 1614 and third data link 1616. Further, ESS 1600 may include network coordinator 1620. In an embodiment, network coordinator 1620 may be a separate device or may be a network coordination application on 10 one of the AP devices of ESS 1600 (e.g., first AP device 1606). Network coordinator 1620 may connect to every AP device via logical links (e.g., network coordinator 1620 may coordinate with first AP device 1606 via first logical link 1622 and with second AP device 1610 via second logical link 1624). Furthermore, network coordinator 1620 may coordinate with AP devices and client devices, collect information of client devices via each AP device in ESS 1600 and 15 share the collected information with each AP device. Further, AP devices may pass this information to each client device in ESS 1600. For example, the information of a client device may include a PACD capability of the client device, a frequency channel associated with an AP device, a current PACD status of the client device, and the like. In an embodiment, the PACD capability may be a capability to indicate if a client device may be a PACD. In an 20 embodiment, the current PACD status may be a status to indicate if the client device is the current PACD.

[0270] Further, in ESS 1600, AP devices (for example, first AP device 1606 and second AP device 1610) may not support sensing. However, client devices in ESS 1600 may support sensing. To detect motion in a sensing space, it may be helpful to sense between client devices 25 that support sensing. For example, it may be advantageous to perform sensing to detect motion – for example, motion of an object 1626 from first BSS 1602 to second BSS 1604 – on links between first client device 1608, second client device 1612 and third client device 1634 to provide a more comprehensive analysis of motion in the sensing space. Sensing link 1632 may be a link for sensing between first client device 1608 and second client device 1612. In an 30 embodiment, sensing link may refer to a link that traverses a sensing area of interest between two networking devices in a Wi-Fi network. Sensing link 1628 may be a link for sensing between first client device 1608 and third client device 1634. Further, sensing link 1630 may be a link for sensing between second client device 1612 and third client device 1634. However, second client device 1612 may be communicating on a different frequency channel from thefrequency channel being used by first client device 1608 and third client device 1634. As a result, second client device 1612 may not receive a transmission made by either first client device 1608 or third client device 1634. In order to form a sensing network among the client devices of ESS 1600, a system and method of present disclosure may be used to select a client 5 device as the sensing initiator with a common frequency channel. Details on the system and method for forming the sensing network have been explained in further paragraphs using FIG. 17 to FIG.23.

[0271] FIG.17 shows an exemplary implementation of system 1700. FIG.17 depicts an exemplary WLAN network showing sensing links on a common frequency channel, according 10 to some embodiments. In an embodiment, system 1700 may be configured to form a sensing network. The process to form the sensing network among the plurality of client devices may include a set of steps, such as discovery of the plurality of client devices, selection of proxy AP client (PACD), common frequency channel selection for WLAN sensing, switching to the common frequency channel and the current selected AP for association and sensing, scheduling 15 the plurality of client devices to enter sleep mode in the data network such that the plurality of client devices may perform sensing, forming the sensing network among the plurality of client devices, performing the sensing measurements, and reporting. In an embodiment, PACD may be a client device that can initiate the forming of a sensing network among the client devices in ESS. In an embodiment, the current selected AP may be an AP with most associated client 20 devices in the ESS.

[0272] Referring to FIG.17 in detail, ESS may include two BSSs, i.e., first BSS 1702 and second BSS 1704, and a network coordinator 1720 (similar to the network coordinator 1620 of FIG.16). First BSS 1702 may include first AP device 1706, first client device 1708 and third client device 1734. Further, second BSS 1704 may include second AP device 1710 and second 25 client device 1712. In an embodiment, first AP device 1706 and second AP device 1710 may communicate with each other via AP data link 1736. In first BSS 1702, first client device 1708 may be communicatively coupled with first AP device 1706 via first data link 1714, and third client device 1734 may be communicatively coupled with first AP device 1706 via third data link 1716. In an embodiment, first data link 1714 and third data link 1716 may be on the 30 common frequency channel (e.g., Frequency Channel 11). In an embodiment, it may be advantageous to perform sensing to detect motion – for example, motion of an object 1726 from first BSS 1702 to second BSS 1704 – on links between first client device 1708, second client device 1712 and third client device 1734 to provide a more comprehensive analysis of motion in the sensing space. Sensing link 1732 may be a link for sensing between the firstclient device 1708 and second client device 1712. In an embodiment, the sensing link may refer to a link that traverses a sensing area of interest between two networking devices in a Wi-Fi network. Sensing link 1728 may be a link for sensing between first client device 1708 and third client device 1734. Further, sensing link 1730 may be a link for sensing between second client 5 device 1712 and third client device 1734.

[0273] At the start of the discovery process, a client device (for example, first client device 1708) may be in an idle mode to scan and collect the information including SSID and BSS identifier (BSSID) of every AP device (for example, first AP device 1706 and second AP device 1710) whose Beacon frame may be received by the client device, the frequency channel 10 with the corresponding bandwidth and BeaconSNR of each Beacon frame. In an embodiment, BeaconSNR may be the signal-to-noise ratio of the received Beacon frames, in decibels (dB). The BeaconSNR may be time-averaged over recent history by a vendor-specific smoothing function (for example, as defined in Table 6-7—ESS Link Parameter Set of Draft P802.11REVme_D5.0). The collected information may be stored locally by the client device 15 (for example, sensing pulse packet storage 528 and / or AP Information Storage 530). Further, the collected information may be used by the sensing algorithm for performing WLAN sensing.

[0274] Referring again to FIG.17 in detail, the client device (for example, first client device 1708) may be in the associated mode to assemble information including SSID and BSSID of the AP device (for example, first AP device 1706), indicator of the client device for 20 sensing, capability of responder to responder (R2R or sensing responder to sensing responder (SR2SR)) sensing, frequency channel associated with the AP device, bandwidth of the frequency channel associated with the AP device, DataFrameSNR of the frequency channel associated with the AP device, PACD capability of the client device, current PACD status and interference profile. In an embodiment, the interference profile may be the average noise plus 25 interference power indicator. Further, the interference profile may correspond to a medium access control (MAC) indication of the average noise plus interference power measured on a channel that meets the two simultaneous conditions i.e., the station (STA) may not be transmitting a frame, and the STA may not be receiving a frame addressed to it (as defined in 3.1 Definitions of Draft P802.11REVme_D5.0). In an embodiment, the DataFrameSNR may 30 be the signal-to-noise ratio of the received Data frames, in dB. The DataFrameSNR may be time-averaged over recent history by a vendor-specific smoothing function (for example, as defined in Table 6-7—ESS Link Parameter Set of Draft P802.11REVme_D5.0). Further, the client device may transmit sensing pulse packets (as defined by this disclosure) to the AP device associated with the client device every few seconds. The sensing pulse packets mayinclude the information collected in the associated mode by the client device, such as a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device. Formats and fields of the sensing pulse packets are defined in TABLE 2. 5 TABLE 2 Order Fields 1 2 3 4 5 6 7 8 9

[0275] As shown in TABLE 2, the SSID and BSSID of the associated AP device may correspond to the network name and identification of the associated AP device to which a client device may be connected for accessing the Internet wirelessly. In an embodiment, the value of 10 the “PACD capability=1” may indicate that the client device is capable to be a proxy AP client device (or “PACD”), while the value of the “PACD capability=0” indicates that the client device is not capable to be a PACD. To facilitate sensing between the plurality of client devices in ESS, there may be PACD to initiate the forming of the sensing network among the plurality of client devices in the ESS. For example, first client device 1708 in Figure 17 may be a PACD. 15 Except the PACD, other client devices may be named as normal client devices (or “NCDs”) in ESS. In an embodiment, NCDs may be other client devices except the PACD in the ESS. For example, the NCDs may be second client device 1712 and third client device 1734. The PACD may provide the AP functions for the sensing network with the NCDs in the ESS. To form a sensing network among the plurality of client devices, one client device referred to as the 20 PACD may be responsible for forming the sensing network on a common frequency channel with the other client devices. The PACD may be selected by the same sensing algorithm on all the plurality of client devices. In order to be the PACD, a client device may be required to bea Multi-AP device, as such the PACD may be selected from a subset of the client devices which are Multi-AP devices. The value of the “current PACD status=1” may indicate that the client device is the current PACD, while the value of the “current PACD status=0” may indicate that the client device is not the current PACD. 5

[0276] Further, a discovery protocol (e.g., Multicast Domain Name System (mDNS) protocol) may be used by an AP or a client device to discover other APs or client devices. With the mDNS protocol, all devices (e.g., APs or client devices) in the network may exchange information with one another via their IP addresses directly. The mDNS protocol is described in RFC 6762 – Multicast DNS (ietf.org). For example, in FIG.17, second client device 1712 10 may be associated with second AP device 1710, such that second AP device 1710 has the information of second client device 1712. With the mDNS protocol, the information of second client device 1712 may be passed to first AP device 1706 via backhaul link 1736 between first AP device 1706 and second AP device 1710. Thus, first AP device 1706 may also have the information of second client device 1712. At the end of the discovery process, every AP device 15 may have client device information (e.g., the information included in the sensing pulse packets) from all the plurality of client devices in the ESS using the discovery protocol (e.g., mDNS protocol). Further, every AP device in the ESS may pass the client device information to any client device via other AP devices in the ESS. In an embodiment, the client device (for example, first client device 1708) may receive client device information associated with the plurality of 20 client devices in the ESS via the AP device associated with client device (for example, first AP device 1706). In an embodiment, the client device information associated with each client device of the plurality of client devices may include PACD capability of the specific client device, a frequency channel associated with the AP device in association with the specific client device, a current PACD status of the specific client device, or any combination thereof. 25

[0277] After the discovery and information sharing by the mDNS protocol, each client device from the plurality of client devices may have the information of the sensing pulse packets from all the client devices. Every client device may use the received client device information of the sensing pulse packets as the inputs to the sensing algorithm within the client device to determine which client device may be selected as the PACD. For example, the client 30 device (for example, first client device 1708) may be configured to select the PACD from among the plurality of client devices according to the received client device information. In an embodiment, the PACD may be associated with a current selected AP (for example, first AP device 1706).

[0278] Every client device from the plurality of client devices may collect sensing pulse packets from the plurality of client devices for a predefined time-period (e.g., 30 seconds). In an embodiment, the sensing pulse packets may be stored in a buffer of the client device (e.g. sensing pulse packet storage 528). At the end of predefined time-period, every client device 5 may examine the information of the sensing pulse packets received from all the client devices. If any of the sensing pulse packets in the time window has the “current PACD status=1”, the client device continues being an NCD (or normal client device). Otherwise, the sensing algorithm within the client device runs the same process to select a PACD capable device as the PACD. In an embodiment, the PACD capable device may be a client device whose PACD 10 capability value=1.

[0279] In selecting the PACD, the client device may be configured to identify the current selected AP as an AP having the largest number of associated client devices from the plurality of client devices. Referring to FIG.17, first AP device 1706 may be the current selected AP with most associated client devices (for example, first client device 1708 and third client device 15 1734) whereas the second AP device 1710 may have only one associated client device, i.e., second client device 1712. Further, the client device may be configured to identify PACD capable devices associated with the current selected AP. The client device may also be configured to select, as the PACD, the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame 20 signal to noise ratios of the PACD capable devices in communications with the current selected AP. In an embodiment, the parameter “DataFrameSNR” may be used for selecting the PACD from the PACD capable devices. The “DataFrameSNR” values of the plurality of client devices of the current selected AP may be listed in an order from smallest value to the largest value with the unit “dB”. A median value indicator is an indicator to indicate the location of a value 25 in a list of values which are in an order from the smallest value to the largest value. For example, a list of “DataFrameSNR” values of the client devices of the current selected AP may be as shown in TABLE 3. TABLE 3 c r C C CClient Device 3 1 -10 Median value-2Client Device 4 0 -5 Median value-1 C C C C C C

[0280] Further, based on the list of “DataFrameSNR” values of PACD capable devices (with PACD capability value=1) of the current selected AP, the PACD capable device with the “DataFrameSNR” value equal or closest to the median value of “DataFrameSNR” may be 5 selected as the current PACD. For example, in TABLE 3, Client Device 5 may be selected as the current PACD because Client Device 5 may be a PACD capable device (with PACD capability value=1) and “DataFrameSNR” value of Client Device 5 may be equal to the median value of “DataFrameSNR” as indicated by the median value indicator. The reason for using the median value of “DataFrameSNR” to select the current PACD from the PACD capable 10 devices of the current selected AP device may be that if the “DataFrameSNR” value of a PACD capable device is equal to or closest to the median value of “DataFrameSNR” of the client devices of the current selected AP, this PACD capable device may have the highest probability to be in the center (or closest to the center) of the client devices of the current selected AP in the sensing space. Thus, the PACD capable device may provide the best coverage when the 15 PACD capable device becomes the proxy AP to form the sensing network between the PACD capable device as the proxy AP and other client devices around the PACD capable device. Further, if two or more PACD capable devices may have the same “DataFrameSNR” value (which is equal or closest to the median value of “DataFrameSNR”), the sensing algorithm may consider other attributes (e.g., minimal value of the interference profile) to select only one of 20 the PACD capable devices as the current PACD.

[0281] Once the PACD is selected, the plurality of client devices may know which device is the current PACD because the plurality of client devices may simultaneously run the same sensing algorithm and compute the same result of the PACD selection. At the same time, the current PACD may continue sending the sensing pulse packets with the "current PACD 25 status=1” to the associated AP device on a periodic basis. The PACD (for example, first client device 1708) may act as the proxy AP and sensing initiator while other NCDs (for example,second client device 1712 and third client device 1734) may act as the non-AP STAs and sensing responders in the sensing measurement sessions. For NCDs, in the next predefined time-period (e.g., the next 30 seconds), all the NCDs may continue to send sensing pulse packets to their associated AP device. The NCDs may also collect and store the sensing pulse 5 packets received from the plurality client devices (e.g., first client device 1708, second client device 1712, and third client device 1734) received from their associated AP into a buffer (e.g., sensing pulse packet storage 564-1).

[0282] At the end of the predefined time-period, each NCD may reexamine the sensing pulse packets from all the client devices. If the “current PACD status=1” in any of the sensing 10 pulse packets from another client device, the client device may continue to be an NCD. Otherwise, the sensing algorithm on every client device may run to select a new PACD. The value of “current PACD status” of the current PACD may be changed from 1 to 0 in one or more situations. In an example, the one or more situations may include one or more new client devices (PACD capable devices or NCDs) being added to the ESS, one or more old client 15 devices being displaced in the ESS, one or more client devices being removed from the ESS, etc. In the one or more situations, the ESS topology, and the median value of “DataFrameSNR” of the client devices associated with the current selected AP device may be changed. Thus, the sensing algorithm may change the results for the selection of PACD. If a new client device may be selected as the new (current) PACD, the old PACD may reset the value of “current 20 PACD status” from 1 to 0.

[0283] In an embodiment, WLAN sensing may work on a frequency channel with a frequency channel bandwidth within a frequency band. The frequency band for WLAN sensing may be 2.4GHz band, 5 GHz band, 6 GHz band, or 60 GHz band, and the like. The frequency channel bandwidth for WLAN sensing may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 25 MHz. Once the current PACD is selected, the frequency channel between the current PACD and the associated AP device may also be selected as a common frequency channel for WLAN sensing via the sensing algorithm on each of the plurality of client devices. In an embodiment, the client device may be configured to select a common frequency channel according to a frequency channel in use by the PACD. 30

[0284] Referring again to FIG.17, first client device 1708 (as the current PACD) may be associated with first AP device 1706 on the frequency channel of first Data Link 1714 (e.g., Frequency Channel 11) which may be selected as the common frequency channel to form the sensing network among the client devices in ESS. In an embodiment, each of the plurality ofclient devices may send a sensing measurement request frame or receive a sensing measurement request frame on the selected common frequency channel.

[0285] After selecting the current selected AP device, the current PACD and the common frequency channel may be selected by the sensing algorithm on each of the plurality of client 5 devices. Further, the sensing algorithm in each of the plurality of client devices (which may not be associated with the current selected AP device) may check the stored BeaconSNR of the current selected AP device. If the client device has the stored BeaconSNR of the current selected AP device and the stored BeaconSNR of the current selected AP device is above a threshold of BeaconSNR, the sensing algorithm may instruct each of the plurality of client 10 devices (which may not be associated with the current selected AP) to switch to the current selected AP device for data transmissions and to form the sensing links (or send sensing transmissions) with the current PACD. The stored BeaconSNR of the current selected AP device above the threshold of BeaconSNR may ensure that the client device may be within the coverage of the current selected AP device and the data link quality is acceptable after the 15 association with the current selected AP device. The threshold of BeaconSNR (e.g., 5 dB, 10 dB, 15 dB, or 20 dB) may be predefined for the sensing algorithm.

[0286] Referring to FIG.17 in detail again, second client device 1712, which may not have been associated with first AP device 1706, may switch to the common frequency channel of first AP device 1706 to associate with the current selected AP device (i.e., first AP device 1706) 20 for data transmissions, forming second data link 1718 and a sensing link (i.e., sensing link 1732) with the current PACD (i.e., first client device 1708) for motion detection, etc.

[0287] Further, the client devices associated with the current selected AP for data communication may need to enter a sleep mode with respect to the data network to form the sensing network. In an embodiment, each of the plurality of client devices associated with the 25 current selected AP may be configured to enter the sleep mode with respect to the current selected AP to perform sensing. In an embodiment, the client device entering the sleep mode may be initiated by sending a data message. Further, entering the sleep mode may be initiated according to predetermined timing. Further, each of the plurality of client devices may also be configured to exit the sleep mode to perform data transmissions with the current selected AP. 30 As defined in Draft P802.11REVme_D5.0, Wireless Network Management (WNM) sleep mode (alternatively called sleep mode) may be an extended power save mode for non-AP STAs in which a non-AP STA may not require to listen to or communicate with the network. The sleep mode may enable a non-AP STA to signal to an AP device that the non-AP STA may sleep for a specified length of time. This may enable a non-AP STA to reduce powerconsumption while the non-AP STA has no traffic to send to or receive from the AP. The period for which the client device may spend in the sleep mode may include one or more TXOPs which may be used for sensing. The process of entering sleep mode may allow the client device to form the sensing network between the current PACD and other NCDs. 5

[0288] In an embodiment, the client device may enter the sleep mode by sending a NullFunc message to the AP device for the purpose of utilizing the 802.11 defined sleep mechanism to indicate that the client device may be momentarily unavailable. In an embodiment, entering sleep mode is initiated according to predetermined timing. Further, a NullFunc message may be used to inform the AP that the client device may not be available 10 for a predefined time period. For example, in the MAC header, a Power Management bit with a value of 1 (e.g., PowerManagement=1) may be included in a NullFunc message. After receiving the NullFunc message, the wireless data communication between the client device and the AP device may be interrupted. In some cases, communication data to the client device may be buffered in the AP device until the client device may exit sleep mode and the 15 communication between the client device and the AP may be re-established. Once the procedure (e.g., the sensing procedure) during the sleep mode is completed, the process of exiting the sleep mode may be performed. For exiting the sleep mode, a second NullFunc message may be sent from the client device to the AP device to inform the AP device that the client device may now be available. For example, by setting the value of the 20 PowerManagement bit to 0 (e.g., PowerManagement=0).

[0289] After the current PACD and the common frequency channel may be selected for WLAN sensing, the plurality of client devices (i.e., the current PACD and current associated NCDs) may be scheduled to enter into the sleep mode at the same time. In an embodiment, the current associated NCD may be an NCD associated with the current selected AP device before 25 PACD selection or the NCD switched to the current selected AP device after PACD selection for sensing. In an embodiment, there may be two options to schedule the plurality of client devices into the sleep mode for sensing i.e., scheduling performed by the PACD and scheduling performed by PACD with assistance of network coordinator 1720.

[0290] For scheduling the plurality of client devices into the sleep mode via the PACD, 30 the PACD may send the NullFunc message to the AP device to signal that the PACD may be going into the sleep mode for a period of time for sensing. This information (or the NullFunc message from the PACD) may be shared with other client devices via the current data link. Once other client devices receive this information (or the NullFunc message from the PACD), other client devices may also enter sleep mode for the same period of time as the PACD. Theother client devices may enter into the sleep mode to form the sensing network with the PACD. The process of scheduling the plurality of client devices into the sleep mode via the PACD may interrupt the data transmissions of the other client devices with their associated AP devices.

[0291] For scheduling the plurality of client devices into the sleep mode via the PACD 5 with assistance of the network coordinator 1720, the PACD may set up a common time period for sensing based on the sensing goal and send the information associated with the common time period to network coordinator 1720. Further, network coordinator 1720 may pass the information associated with the common time period to every client device. Once the plurality client devices receive the information associated with the common time period, each of the 10 plurality of client devices may send the NullFunc message to the associated AP device to indicate that the plurality of client devices are entering into the sleep mode for the common time period. This option may also interrupt the data transmissions of the other client devices with their associated APs.

[0292] After the current PACD and the common frequency channel may be selected for 15 sensing and the NCDs may be switched to the current selected AP device and the common frequency channel, a sensing network may be formed during the sleep mode (based on the sensing goal) among the PACD as the sensing initiator and the current associated NCDs as the sensing responders in the ESS. The PACD as the sensing initiator may initiate a trigger-based (TB) sensing procedure by transmitting a Sensing Measurement Request frame. Further, the 20 sensing roles of sensing transmitter and sensing receiver may be assigned by the Sensing Measurement Request Frame during the sensing measurement session setup, as explained with reference to FIG.7A to FIG.7C.

[0293] In an embodiment, the client device may initiate a trigger based sensing procedure with one of the plurality of client devices. In an embodiment, the plurality of client devices 25 may include the client device, which is selected as the PACD. Further, the client device may be configured to receive a sensing transmission from one of the plurality of client devices. The current PACD may be selected as the sensing initiator and the current associated NCDs may be selected as the sensing responders in the ESS to perform sensing roles (e.g. sensing transmitter or / and sensing receiver) using a sensing measurement request frame during a 30 sensing measurement session. The current PACD as the sensing initiator may initiate the trigger-based sensing. The sensing measurements may be performed at the sensing receiver and the sensing measurement report may be transferred to the sensing application. In an embodiment, the sensing application may be pre-installed in each of the plurality of client devices in the ESS. For example, the client device (selected as the PACD) may initiate a triggerbased sensing procedure with one of the plurality of client devices. Further, the client device may receive a sensing transmission or a sensing measurement report from the one of the plurality of client devices.

[0294] Referring to FIG. 17 in detail again, different types of sensing measurement 5 exchanges may be performed between the current PACD (e.g., first client device 1708) as the proxy AP and the sensing initiator, and one or more current associated NCDs as the non-AP STAs (e.g., second client device 1712 or / and third client device 1734). A TB sensing measurement exchange may be performed between the current PACD (e.g., first client device 1708) and another current associated NCD for sensing (e.g., second client device 1712 or / and 10 third client device 1734). For example, the PACD (e.g., first client device 1708) may act as a proxy AP and sensing initiator, and one or more current associated NCDs (e.g., second client device 1712 or / and third client device 1734) may act as non-AP STA sensing responders and perform sensing transmissions or sensing measurement reports on sensing link 1732 and / or sensing link 1728. 15

[0295] In a TB sensing measurement exchange with a TF sounding phase, an SR2SR variant may be performed between two current associated NCDs for sensing (e.g., second client device 1712 and third client device 1734). For example, the current PACD (e.g., first client device 1708) may act as a proxy AP and sensing initiator to trigger the two current associated NCDs (e.g., second client device 1712 and third client device 1734) as the non-AP STA sensing 20 responders and perform sensing transmissions on sensing link 1730.

[0296] Further, the client device may initiate a sensing session between two of the plurality of client devices. The client device may receive a sensing measurement report from the one of the two of the plurality of client devices.

[0297] In an embodiment, the plurality of client devices may include the client device, and 25 the client device is not selected as the PACD. Further, the client device may be configured to receive, from the PACD, a sensing trigger message to initiate a trigger based sensing procedure with the PACD. Furthermore, the client device may be configured to transmit, to the PACD, a sensing measurement report or a sensing transmission. In an embodiment, the client device may be configured to receive, from the PACD, a sensing trigger message to initiate a sensing 30 procedure with one client device from the plurality of client devices. For example, sensing transmissions may be received at the sensing receiver and sensing measurements may be performed at the sensing receiver. Since the current PACD may be the sensing initiator, the sensing measurement report may be transferred to the sensing initiator (i.e., the current PACD) from the sensing receiver. There may be multiple sensing receivers. For example, if the sensingapplication is installed on the current PACD, which is acting as sensing initiator and sensing receiver, and the sensing application is configured for normal TB sensing (which is not the R2R sensing), the sensing measurement report may be transferred to the sensing application within the current PACD via MLME primitives during the sensing measurement session. 5

[0298] Further, if the sensing application may be installed on the current PACD as the sensing initiator and the sensing transmitter while a current associated NCD may be the sensing receiver in normal TB sensing (which is not the R2R sensing), the sensing measurement report may be transferred from the sensing receiver to the sensing application at the current PACD via the Over-the-Air (OTA) sensing measurement reports during the sensing measurement 10 session. If the sensing application may be installed on the current PACD as the sensing initiator in the TB R2R sensing while other current associated NCDs may be sensing responders, the sensing measurement report may be transferred from the sensing receiver (e.g., one of the current associated NCDs or sensing responders) in TB R2R sensing to the sensing application at the current PACD via the OTA sensing measurement reports during the sensing 15 measurement session.

[0299] Furthermore, if the client device is not associated with the current selected AP, then responsive to a beacon signal to noise ratio (e.g., BeaconSNR) between the client device and the current selected AP exceeding a threshold (e.g., threshold of BeaconSNR) associated with the current selected AP the client device may determine to switch to the current selected AP 20 for association and sensing. For example, client device 1712 in FIG.17 might not have been associated with the AP 1706 in FIG.17 and it may be responsive to a beacon signal to noise ratio (e.g., BeaconSNR) between client device 1712 and AP 1706 exceeding a threshold (e.g., threshold of BeaconSNR), associating with AP 1706 that determined that client device 1712 would switch to AP 1706 for association and sensing. 25

[0300] In operation, a system (e.g., system 1700) may be configured to select a client device as the PACD and sensing initiator with a common frequency channel to form a sensing network among the client devices. The processes to form the sensing network among the client devices may include the discovery of the plurality of client devices, selection of the PACD, common frequency channel selection for sensing, switching to the common frequency channel 30 and the current selected AP for association and sensing, scheduling the client devices to enter sleep mode in the data network, forming the sensing network among the client devices, performing the sensing measurements and reporting. The sensing algorithm pre-installed within the client device may determine which client device may be selected as the PACD with the information shared with every client device via the mDNS protocol. The two steps to selectthe PACD may include selecting an AP with most associated client devices and selecting the PACD from the PACD capable devices associated with the current selected AP based on the parameters (e.g., “DataFrameSNR”).

[0301] FIG.18 depicts an exemplary flowchart for establishing a Wi-Fi sensing network 5 carried out by a client device, according to some embodiments. In an implementation, flowchart 1800 may be carried out by a client device (for example, client device 502 in FIG. 5).

[0302] In a brief overview of an implementation of flowchart 1800, at step 1802, sensing pulse packet including PACD capability of client device, frequency channel of associated AP, 10 and current PACD status of client device may be transmitted to associated AP device. Further, at step 1804, client device information associated with a plurality of client devices may be received from an AP device in an extended service set. At step 1806, a proxy AP client device (PACD) may be selected from among the plurality of client devices according to the client device information, the PACD being associated with a current selected AP. At step 1808, a 15 common frequency channel may be selected according to a frequency channel in use by the PACD. At step 1810, a sensing measurement request frame may be sent on the selected common frequency channel or at step 1812, a sensing measurement request frame may be received on the selected common frequency channel.

[0303] Step 1802 includes transmitting sensing pulse packet including the PACD 20 capability of client device, the frequency channel of associated AP, and the current PACD status of client device to the associated AP device. According to some implementation, client device 502 may be configured to transmit sensing pulse packet including the PACD capability of client device 502, the frequency channel of associated AP (for example, first AP device 1706), and the current PACD status of client device 502 to the associated AP device (for 25 example, first AP device 1706).

[0304] Step 1804 includes receiving, from the associated AP device, the client device information associated with the plurality of client devices in the extended service set. According to some implementation, client device 502 may be configured to receive, from the associated AP device (for example, first AP device 1706), the client device information 30 associated with the plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) in the ESS. In an embodiment, the client device information associated with each specific client device of the plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) includes PACD capability of the specificclient device, a frequency channel associated with the AP device in association with the specific client device, a current PACD status of the specific client device, or any combination thereof.

[0305] At step 1806, the PACD may be selected from among the plurality of client devices according to the client device information, the PACD being associated with a current selected 5 AP. According to some implementation, client device 502 may be configured to select the PACD (for example, first client device 1708 in FIG.17) from among the plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) according to the client device information using sensing controller 510. In an embodiment. the PACD (for example, first client device 1708) being associated with a current selected AP (for example, 10 first AP device 1706).

[0306] At step 1808, a common frequency channel may be selected according to the frequency channel in use by the PACD. According to some implementation, client device 502 may be configured to select the common frequency channel according to the frequency channel in use by the PACD (for example, first client device 1708) by sensing application 522 in FIG. 15 5. In an embodiment, the common frequency channel may be a channel in use between the PACD (for example, first client device 1708) and the current selected AP (for example, first AP device 1706) associated with the PACD (for example, first client device 1708).

[0307] At step 1810, a sensing measurement request frame may be sent on the selected common frequency channel. According to some implementation, client device 502 may be 20 configured to send the sensing measurement request frame on the selected common frequency channel using sensing agent 520.

[0308] At step 1812, the sensing measurement request frame may be received on the selected common frequency channel. According to some implementation, client device 502 may be configured to receive the sensing measurement request frame on the selected common 25 frequency channel using sensing agent 520.

[0309] While the above steps shown in FIG.18 are described in a particular sequence, the steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 18, which are already covered in the description related to FIG.1 to FIG.17 are not discussed again in detail here for 30 the sake of brevity.

[0310] FIG.19 depicts an exemplary flowchart for selecting the PACD, according to some other embodiments. In an implementation, flowchart 1900 may be carried out by a client device (for example, client device 502).

[0311] In a brief overview of an implementation of flowchart 1900, at step 1902, the current selected AP may be identified as an AP which is having a largest number of associated client devices from the plurality of client devices. At step 1904, PACD capable devices associated with the current selected AP may be identified. Furthermore, at step 1906, the PACD 5 capable device, may be selected as PACD, having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP.

[0312] Step 1902 includes identifying the current selected AP as having the largest number of associated client devices from the plurality of client devices. According to some 10 implementation, client device 502 may be configured to identify the current selected AP (for example, first AP device 1706) as having a largest number of associated client devices from the plurality of client devices (for example, client device 502 and additional client devices 504- (1-N)) using the sensing application 522.

[0313] Step 1904 includes identifying PACD capable devices associated with the current 15 selected AP. According to some implementation, client device 502 may be configured to identify PACD capable devices associated with the current selected AP (for example, first AP device 1706) using sensing application 522.

[0314] Step 1906 includes selecting as the PACD the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP closest to a mean 20 of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP. According to some implementation, client device 502 may be configured to selecting, as the PACD, the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP (for example, first AP device 1706) closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications 25 with the current selected AP (for example, first AP device 1706). In an embodiment, the client device 502 may select the PACD using sensing application 522.

[0315] While the above steps shown in FIG.19 are described in a particular sequence, the steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 19, which are already 30 covered in the description related to FIG.1 to FIG.18 are not discussed again in detail here for the sake of brevity.

[0316] FIG.20 to FIG.23 depict exemplary flowcharts of entering and exiting the sleep mode carried out by the client device, according to some other embodiments. Specifically, FIG. 20 depicts an exemplary flowchart for TB (trigger-based) sensing with TF (trigger frame)sounding. FIG.21 depicts an exemplary flowchart for TB sensing with NDPA sounding. FIG. 23 depicts an exemplary flowchart for TB R2R sensing. For the sake of brevity, FIG.20 to FIG.23 are explained together. In an implementation, flowchart 2000, flowchart 2100, and flowchart 2200 may be carried out by a client device (for example, client device 502) which 5 may be selected as a PACD.

[0317] In a brief overview of an implementation of flowchart 2000, at step 2002, a sleep mode may be entered with respect to the current selected AP to perform sensing. At step 2004, a trigger based sensing procedure may be initiated by the client device with one of the plurality of client devices. Further, at step 2006, a sensing transmission may be received from one of the 10 plurality of client devices. Furthermore, at step 2008, the sleep mode may be exited to perform data transmissions with the current selected AP.

[0318] Step 2002 includes entering the sleep mode with respect to the current selected AP device to perform sensing. According to some implementation, client device 502 may be configured to enter the sleep mode with respect to the current selected AP device to perform 15 sensing (for example, first AP device 1706) using sensing agent 520. In an embodiment, entering the sleep mode may be initiated responsive to receipt of a data message. Further, entering the sleep mode may be initiated according to predetermined timing.

[0319] Step 2004 includes initiating, by the client device, the trigger based sensing procedure with one of the plurality of client devices. According to some implementations, 20 client device 502 may be configured to initiate the trigger based sensing procedure with one of the plurality of client devices (for example, client device 502 and additional client devices 504- (1-N)) using sensing agent 520. In an embodiment, the plurality of client devices may include the client device, and the client device is selected as the PACD.

[0320] Step 2006 includes receiving the sensing transmission from the one of the plurality 25 of client devices. According to some implementation, client device 502 may be configured to receive the sensing transmission from the one of the plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) using sensing agent 520.

[0321] Step 2008 includes exiting the sleep mode to perform data transmissions with the current selected AP. According to some implementation, client device 502 may be configured 30 to exit the sleep mode to perform data transmissions with the current selected AP (for example, first AP device 1706).

[0322] While the above steps shown in FIG.20 are described in a particular sequence, the steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 20, which are alreadycovered in the description related to FIG.1 to FIG.19 are not discussed again in detail here for the sake of brevity.

[0323] In a brief overview of an implementation of flowchart 2100, at step 2102, a sleep mode may be entered with respect to the current selected AP to perform sensing. At step 2104, 5 a trigger based sensing procedure may be initiated by the client device with one of the plurality of client devices. Further, at step 2106, a sensing measurement report may be received from the one of the plurality of client devices. Furthermore, at step 2108, the sleep mode may be exited to perform data transmissions with the current selected AP.

[0324] Step 2102 includes entering the sleep mode with respect to the current selected AP 10 device to perform sensing. According to some implementation, client device 502 may be configured to enter the sleep mode with respect to the current selected AP device to perform sensing (for example, first AP device 1706) using sensing agent 520. In an embodiment, entering the sleep mode may be initiated responsive to receipt of a data message. Further, entering the sleep mode may be initiated according to predetermined timing. 15

[0325] Step 2104 includes initiating, by the client device, the trigger based sensing procedure with one of a plurality of client devices. According to some implementation, client device 502 may be configured to initiate the trigger based sensing procedure with one of the plurality of client devices (for example, client device 502 and additional client devices 504-(1- N)) using sensing agent 520. 20

[0326] Step 2106 includes receiving the sensing measurement report from the one of the plurality of client devices. According to some implementation, client device 502 may be configured to receive the sensing transmission from the one of the plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) using sensing agent 520. 25

[0327] Step 2108 includes exiting the sleep mode to perform data transmissions with the current selected AP. According to some implementation, client device 502 may be configured to exit the sleep mode to perform data transmissions with the current selected AP (for example, first AP device 1706).

[0328] While the above steps shown in FIG.21 are described in a particular sequence, the 30 steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 21, which are already covered in the description related to FIG.1 to FIG.20 are not discussed again in detail here for the sake of brevity.

[0329] In a brief overview of an implementation of flowchart 2200, at step 2202, a sleep mode may be entered with respect to the current selected AP to perform sensing. At step 2204, sensing session may be initiated between two of a plurality of client devices. Further, at step 2206, a sensing measurement report may be received from the one of the plurality of client 5 devices. Furthermore, at step 2208, the sleep mode may be exited to perform data transmissions with the current selected AP.

[0330] Step 2202 includes entering the sleep mode with respect to the current selected AP device to perform sensing. According to some implementation, client device 502 may be configured to enter the sleep mode with respect to the current selected AP device to perform 10 sensing (for example, first AP device 1706) using sensing agent 520. In an embodiment, entering the sleep mode may be initiated responsive to receipt of a data message. Further, entering the sleep mode may be initiated according to predetermined timing.

[0331] Step 2204 includes initiating the sensing session between two of a plurality of client devices. According to some implementation, client device 502 may be configured to initiate 15 the sensing session between two of a plurality of client devices (for example, client device 502 and additional client devices 504-(1-N)) using sensing agent 520.

[0332] Step 2206 includes receiving the sensing measurement report from one of the plurality of client devices. According to some implementation, client device 502 may be configured to receive the sensing transmission from one of the plurality of client devices (for 20 example, client device 502 and additional client devices 504-(1-N)) using sensing agent 520.

[0333] Step 2208 includes exiting the sleep mode to perform data transmissions with the current selected AP. According to some implementation, client device 502 may be configured to exit the sleep mode to perform data transmissions with the current selected AP (for example, first AP device 1706). 25

[0334] While the above steps shown in FIG.22 are described in a particular sequence, the steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 22, which are already covered in the description related to FIG.1 to FIG.21 are not discussed again in detail here for the sake of brevity. 30

[0335] FIG.23 depicts an exemplary flowchart for establishing the Wi-Fi sensing network carried out by the client device, according to some embodiments. In an implementation, flowchart 2300 may be carried out by a client device (for example, client device 502) which may not be selected as a PACD.

[0336] In a brief overview of an implementation of flowchart 2300, at step 2302, a sensing trigger message may be received from the PACD to initiate a trigger based sensing procedure with the PACD. At step 2304, a sensing measurement report or a sensing transmission may be transmitted to the PACD. In another embodiment, at step 2306 a sensing trigger message may 5 be received from the PACD to initiate a sensing procedure with one client device from a plurality of client devices. In an embodiment, the plurality of client devices may include the client device, and the client device is not selected as the PACD.

[0337] Step 2302 includes receiving from the PACD the sensing trigger message to initiate the trigger based sensing procedure with the PACD. According to some implementation, client 10 device 502 may be configured to receive from the PACD (for example, client device 504-1), the sensing trigger message to initiate the trigger based sensing procedure with the PACD (for example, client device 504-1) using sensing agent 520.

[0338] Step 2304 includes transmitting to the PACD the sensing measurement report or the sensing transmission. According to some implementation, client device 502 may be 15 configured to transmit, to the PACD (for example, client device 504-1), the sensing measurement report or the sensing transmission using sensing agent 520.

[0339] Further, step 2306 may be performed in alternative to Step 2302 and Step 2304. Step 2306 includes receiving from the PACD (for example, client device 504-1) a sensing trigger message which may initiate a sensing procedure with one client device from a plurality 20 of client devices. According to some implementation, client device 502 may be configured to receive from the PACD (for example, client device 504-1) the sensing trigger message to initiate the sensing procedure with one client device from the plurality of client devices(for example, client device 502 and additional client devices 504-(1-N)).

[0340] While the above steps shown in FIG.23 are described in a particular sequence, the 25 steps may occur in variations to the sequence in accordance with various embodiments of the present disclosure. Further, details related to various steps of FIG. 23, which are already covered in the description related to FIG.1 to FIG.22 are not discussed again in detail here for the sake of brevity.

[0341] Embodiment 1 is a method for establishing a Wi-Fi sensing network carried out by 30 a client device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions, the method comprising: receiving, from an associated access point (AP), client device information associated with a plurality of client devices in an extended service set; selecting a proxy AP client device (PACD) from among the plurality of client devices according to the client device information, the PACD being associated with acurrent selected AP; selecting a common frequency channel according to a frequency channel in use by the PACD, and one of sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel.

[0342] Embodiment 2 is the method of embodiment 1, further comprising: transmitting, to 5 the associated AP, a sensing pulse packet including at least: a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device, wherein the client device information associated with each specific client device of the plurality of client devices includes at least: PACD capability of the specific client device, a frequency channel associated with the AP in association with the specific client device, and a 10 current PACD status of the specific client device.

[0343] Embodiment 3 is the method of embodiment 1 or embodiment 2, wherein selecting the PACD includes: identifying the current selected AP as having a largest number of associated client devices from the plurality of client devices, identifying PACD capable devices associated with the current selected AP, and selecting, as the PACD, the PACD capable device 15 having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP.

[0344] Embodiment 4 is the method of any of embodiments 1-3, wherein the common frequency channel is a channel in use between the PACD and the current selected AP associated 20 with the PACD.

[0345] Embodiment 5 is the method of any of embodiments 1-4, further comprising: entering a sleep mode with respect to the current selected AP to perform sensing, and exiting the sleep mode to perform data transmissions with the current selected AP.

[0346] Embodiment 6 is the method of embodiment 5, wherein entering the sleep mode is 25 initiated by sending a data message.

[0347] Embodiment 7 is the method of embodiment 6, wherein entering the sleep mode is initiated according to predetermined timing.

[0348] Embodiment 8 is the method of any of embodiments 1-7, wherein the plurality of client devices includes the client device, and the client device is selected as the PACD. 30

[0349] Embodiment 9 is the method of embodiment 8, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing transmission from the one of the plurality of client devices.

[0350] Embodiment 10 is the method of embodiment 8, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing measurement report from the one of the plurality of client devices. 5

[0351] Embodiment 11 is the method of embodiment 8, further comprising: initiating, by the client device, a sensing session between two of the plurality of client devices, and receiving a sensing measurement report from the one of the two of the plurality of client devices.

[0352] Embodiment 12 is the method of any of embodiments 1-11, wherein the plurality of client devices includes the client device, and the client device is not selected as the PACD. 10

[0353] Embodiment 13 is the method of embodiment 12, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with the PACD; and transmitting, to the PACD, a sensing measurement report or a sensing transmission.

[0354] Embodiment 14 is the method of embodiment 12, further comprising: receiving, 15 from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with one client device from the plurality of client devices.

[0355] Embodiment 15 is the method of any of embodiments 1-14, further comprising, if the client device is not associated with the current selected AP, responsive to a beacon signal to noise ratio between the client device and the current selected AP surpassing a threshold, 20 associating with the current selected AP.

[0356] Embodiment 16 is a system for establishing a Wi-Fi sensing network comprising a client device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions for: receiving, from an associated access point (AP), client device information associated with a plurality of client devices in an extended service set; 25 selecting a proxy AP client device (PACD) from among the plurality of client devices according to the client device information, the PACD being associated with a current selected AP; selecting a common frequency channel according to a frequency channel in use by the PACD, and one of sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel. 30

[0357] Embodiment 17 is the system of embodiment 16, further comprises: transmitting, to the associated AP, a sensing pulse packet including at least: a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device, wherein the client device information associated with each specific client device of the plurality of client devices includes at least: PACD capability of the specific client device, afrequency channel associated with the AP in association with the specific client device, and a current PACD status of the specific client device.

[0358] Embodiment 18 is the system of embodiment 16 or 17, wherein selecting the PACD includes: identifying the current selected AP as having a largest number of associated client 5 devices from the plurality of client devices, identifying PACD capable devices associated with the current selected AP, and selecting, as the PACD, the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP. 10

[0359] Embodiment 19 is the system of any of embodiments 16-18, wherein the common frequency channel is a channel in use between the PACD and the current selected AP associated with the PACD.

[0360] Embodiment 20 is the system of any of embodiments 16-19, further comprising: entering a sleep mode with respect to the current selected AP to perform sensing with the 15 PACD, and exiting the sleep mode to perform data transmissions with the current selected AP.

[0361] Embodiment 21 is the system of embodiment 20, wherein entering the sleep mode is initiated by sending a data message.

[0362] Embodiment 22 is the system of embodiment 21, wherein entering the sleep mode is initiated according to predetermined timing. 20

[0363] Embodiment 23 is the system of any of embodiments 16-22, wherein the plurality of client devices includes the client device, and the client device is selected as the PACD.

[0364] Embodiment 24 is the system of embodiment 23, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing transmission from the one of the plurality of client 25 devices.

[0365] Embodiment 25 is the system of embodiment 23, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing measurement report from the one of the plurality of client devices. 30

[0366] Embodiment 26 is the system of embodiment 23, further comprising: initiating, by the client device, a sensing measurement exchange between two of the plurality of client devices, and receiving a sensing measurement report from the one of the two of the plurality of client devices.

[0367] Embodiment 27 is the system of any of embodiments 16-26, wherein the plurality of client devices includes the client device, and the client device is not selected as the PACD.

[0368] Embodiment 28 is the system of embodiment 27, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement 5 exchange with the PACD; and transmitting, to the PACD, a sensing measurement report or a sensing transmission.

[0369] Embodiment 29 is the system of embodiment 27, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with one client device from the plurality of client devices. 10

[0370] Embodiment 30 is the system of embodiment 27, further comprising, if the client device is not associated with the current selected AP, responsive to a beacon signal to noise ratio between the client device and the current selected AP surpassing a threshold, associating with the current selected AP.

[0371] While various embodiments of the methods and systems have been described, these 15 embodiments are illustrative and in no way limit the scope of the described methods or systems. Those having skill in the relevant art can effect changes to form and details of the described methods and systems without departing from the broadest scope of the described methods and systems. Thus, the scope of the methods and systems described herein should not be limited by any of the illustrative embodiments and should be defined in accordance with the 20 accompanying claims and their equivalents.

Claims

CLAIMS We claim 5 1. A method for establishing a Wi-Fi sensing network carried out by a client device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions, the method comprising: receiving, from an associated access point (AP), client device information associated with a plurality of client devices in an extended service set; selecting a proxy AP client device (PACD) from among the plurality of client devices according to the client device information, the PACD being associated with a current selected AP; selecting a common frequency channel according to a frequency channel in use by the PACD; and one of sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel.

2. The method of claim 1, further comprising: transmitting, to the associated AP, a sensing pulse packet including at least: a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device, wherein the client device information associated with each specific client device of the plurality of client devices includes at least: PACD capability of the specific client device, a frequency channel associated with the AP in association with the specific client device, and a current PACD status of the specific client device.

3. The method of claim 1, wherein selecting the PACD includes: identifying the current selected AP as having a largest number of associated client devices from the plurality of client devices, identifying PACD capable devices associated with the current selected AP, andselecting, as the PACD, the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP. 5 4. The method of claim 1, wherein the common frequency channel is a channel in use between the PACD and the current selected AP associated with the PACD.

5. The method of claim 1, further comprising: entering a sleep mode with respect to the current selected AP to perform sensing, and exiting the sleep mode to perform data transmissions with the current selected AP.

6. The method of claim 5, wherein entering the sleep mode is initiated by sending a data message.

7. The method of claim 6, wherein entering the sleep mode is initiated according to predetermined timing.

8. The method of claim 1, wherein the plurality of client devices includes the client device, and the client device is selected as the PACD.

9. The method of claim 8, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing transmission from the one of the plurality of client devices.

10. The method of claim 8, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing measurement report from the one of the plurality of client devices.

11. The method of claim 8, further comprising: initiating, by the client device, a sensing session between two of the plurality of client devices, andreceiving a sensing measurement report from the one of the two of the plurality of client devices.

12. The method of claim 1, wherein the plurality of client devices includes the client device, 5 and the client device is not selected as the PACD.

13. The method of claim 12, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with the PACD; and transmitting, to the PACD, a sensing measurement report or a sensing transmission.

14. The method of claim 12, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with one client device from the plurality of client devices.

15. The method of claim 1, further comprising, if the client device is not associated with the current selected AP, responsive to a beacon signal to noise ratio between the client device and the current selected AP surpassing a threshold, associating with the current selected AP.

16. A system for establishing a Wi-Fi sensing network comprising a client device including a transmitting antenna, a receiving antenna, and at least one processor configured to execute instructions for: receiving, from an associated access point (AP), client device information associated with a plurality of client devices in an extended service set; selecting a proxy AP client device (PACD) from among the plurality of client devices according to the client device information, the PACD being associated with a current selected AP; selecting a common frequency channel according to a frequency channel in use by the PACD; and one of sending a sensing measurement request frame or receiving a sensing measurement request frame on the selected common frequency channel.

17. The system of claim 16, further comprises: transmitting, to the associated AP, a sensing pulse packet including at least:a PACD capability of the client device, a frequency channel of the associated AP, and a current PACD status of the client device, wherein the client device information associated with each specific client device of the plurality 5 of client devices includes at least: PACD capability of the specific client device, a frequency channel associated with the AP in association with the specific client device, and a current PACD status of the specific client device.

18. The system of claim 16, wherein selecting the PACD includes: identifying the current selected AP as having a largest number of associated client devices from the plurality of client devices, identifying PACD capable devices associated with the current selected AP, and selecting, as the PACD, the PACD capable device having a data frame signal to noise ratio in communications with the current selected AP closest to a mean of data frame signal to noise ratios of the PACD capable devices in communications with the current selected AP.

19. The system of claim 16, wherein the common frequency channel is a channel in use between the PACD and the current selected AP associated with the PACD.

20. The system of claim 16, further comprising: entering a sleep mode with respect to the current selected AP to perform sensing with the PACD, and exiting the sleep mode to perform data transmissions with the current selected AP.

21. The system of claim 20, wherein entering the sleep mode is initiated by sending a data message.

22. The system of claim 21, wherein entering the sleep mode is initiated according to predetermined timing.

23. The system of claim 16, wherein the plurality of client devices includes the client device, and the client device is selected as the PACD.

24. The system of claim 23, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and 5 receiving a sensing transmission from the one of the plurality of client devices.

25. The system of claim 23, further comprising: initiating, by the client device, a trigger based sensing measurement exchange with one of the plurality of client devices, and receiving a sensing measurement report from the one of the plurality of client devices.

26. The system of claim 23, further comprising: initiating, by the client device, a sensing measurement exchange between two of the plurality of client devices, and receiving a sensing measurement report from the one of the two of the plurality of client devices.

27. The system of claim 16, wherein the plurality of client devices includes the client device, and the client device is not selected as the PACD.

28. The system of claim 27, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with the PACD; and transmitting, to the PACD, a sensing measurement report or a sensing transmission.

29. The system of claim 27, further comprising: receiving, from the PACD, a sensing trigger message to initiate a trigger based sensing measurement exchange with one client device from the plurality of client devices.

30. The system of claim 27, further comprising, if the client device is not associated with the current selected AP, responsive to a beacon signal to noise ratio between the client device and the current selected AP surpassing a threshold, associating with the current selected AP.

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