Method for WLAN sensing, apparatus for WLAN sensing and non-transitory computer-readable storage medium

US Patent: US2023403589A1

Publication Date: 2023-12-14

Assignee: Beijing Xiaomi Mobile Software Co Ltd

The period request frame includes a first period information element and it is used to perform periodic WLAN sensing by the station. The WLAN sensing period response frame includes a second period information element of the AP.

The inclusion of capability information exchange ensures devices are aware of each other’s sensing capabilities, optimizing WLAN sensing operations.

WLAN sensing period request frame includes at least one of the following:

The period information element ID, the byte length, the WLAN sensing period offset, the WLAN sensing duration, the WLAN sensing interval, the number of WLAN sensing repetition, and the connection information.

Solution

• The solution relates to a method for executing WLAN sensing to overcome mutual interference.
• Using period request frames, period response frames and the capability information exchange to mitigate interference and enhance communication efficiency between devices.
• The station sends determined WLAN sensing period request frame, the AP sends a WLAN sensing period response frame to the station in response to the received WLAN sensing period request frame.
• If the second period information element is the same as the first period information element of the station, it is determined that the AP agrees to the WLAN sensing period request of the station.
• The capability supported by the station and AP is exchanged.

Application

• Wireless communications, specifically for executing WLAN sensing in environments like family or enterprise settings where location discovery, proximity detection, and presence detection are crucial.
• Could be extended to various IoT applications, wearable devices, vehicle-mounted systems, and smart home technologies requiring efficient and precise location or proximity-based services.

Comment

• The method is suitable for reducing communication interference of other stations.
• A WLAN sensing message may be periodically initiated within a preset or defined period by negotiating a WLAN sensing period between the station and the AP.

 

Communication method and communication apparatus for wireless local area network sensing measurement

WO Patent: WO2023065308A1

Publication Date: 2023-04-27

Assignee:  Beijing Xiaomi Mobile Software Co Ltd

The solutions enable different measurement modes in different sensing measurement events, allowing the process of WLAN sensing measurement to be performed efficiently.

Solution

• The solution relates to a communication method and device that enable efficient WLAN sensing measurements by addressing the lack of a defined mechanism for utilizing different perception measurement events in the WLAN sensing measurement process.
• Determining and sending structured perception measurement procedure establishment message frames (each tailored to specific sensing measurement events and procedures) enable efficient WLAN sensing measurements.
• Information associated within these frames is associated with the perception measurement events, facilitating targeted WLAN awareness measurements.

Application

• The application of the solution can be in the field of wireless local area network (WLAN) awareness measurement.
• The applications include location discovery in dense environments, proximity detection, and presence detection in settings such as homes and enterprises

Comment

WO Patent: WO2023049962A1

Publication Date: 2023-04-06

Assignee: Newsouth Innovations Pty Limited

Enables early detection of fires and changes in temperature, enhancing safety and mitigating damage without the need for traditional fire-specific devices.

Utilizes widespread Wi-Fi infrastructure, making the system accessible and cost-effective.

Solution

• The solution relates to fire detection and monitoring environmental conditions in indoor spaces, leveraging the ubiquity of Wi-Fi technology.
• It employs wireless networking signals, specifically utilizing channel state information (CSI) amplitudes, to detect changes in temperature and diagnose the presence of fire or other environmental changes.
• The system uses wireless communications channel state information (CSI) to detect temperature changes and fire presence. It involves training classifiers to recognize patterns associated with temperature shifts or fire causes, based on CSI amplitudes from wireless networking signals.
• The method includes selecting specific subcarriers with a strong relationship between amplitude changes and temperature variations.

Application

Broad applicability in data centers, commercial premises, and residential settings for environmental monitoring, including humidity, occupancy, and other atmospheric conditions beyond temperature changes.

Comment

• The solution is suitable for early detection of fires and changes in temperature, enhancing safety and mitigating damage without the need for traditional fire-specific devices.
• Utilizes widespread WiFi infrastructure, making the system accessible and cost-effective.

Wireless network Wi-Fi sensing method and system, and computer device

WO Patent: WO2024021824A1

Publication Date: 2024-02-01

Assignee: ZTE Corporation

The scene state may be an activity recognition, gesture recognition or fall detection scene, or may be a change in the relative distance and speed of the object and the antenna.

Compared with related technologies, it can alleviate the problem of Wi-Fi perception degradation caused by multipath effects and achieve multi-dimensional and high-precision Wi-Fi perception.

Spectrograms can reflect the mapping relationship between spatial changes and overall signal changes, which is beneficial to the perception and identification of Wi-Fi signals.

Solution

• The solution relates to a Wi-Fi sensing method to alleviate the problem of Wi-Fi perception degradation caused by multipath effects and achieve multi-dimensional and high-precision Wi-Fi perception.
• The solution obtains Wi-Fi signals transmitted along a path, and detects the scene status of the Wi-Fi signal coverage area in real time, and then performs signal processing on the Wi-Fi signal according to the scene status to generate a spectrogram.
• The spectrogram can reflect the mapping relationship between spatial changes and signal changes.
• Wi-Fi signals which can be used to implement coarse-grained and fine-grained sensing tasks are identified based on the spectrogram.
• The spectrogram is generated based on a plurality of the principal component signals.

Application

The wireless network Wi-Fi sensing system can be applied to the Wi-Fi chip of the transceiver to support all projects that can obtain channel state information (CSI) or passive Wi-Fi radar (PWR) information collection.

Comment

The solution is suitable for alleviating indoor multipath effect.

 

System and Method for Sensing an Environment

US Patent: US2023072968A1

Publication Date: 2023-03-09

Assignee: Northeastern University

ReWiS may leverage few-shot learning (FSL) as the inference engine, which (i) reduces the need for extensive data collection and application-specific feature extraction and (ii) can rapidly generalize to new tasks by only leveraging a few new samples. It uses singular value decomposition (SVD) to make the FSL input constant irrespective of the number of receiver antennas.

A fundamental difference of ReWiS with respect to existing work is to leverage spatial diversity (i.e., multiple receivers and multiple antennas per receiver), time diversity (i.e., multiple CSI measurements) and increased subcarrier resolution to significantly improve the robustness of the sensing process.

Core design principles behind the ReWiS may (i) leverage multi-antenna, multi-receiver diversity, as well as fine-grained frequency resolution to improve the overall robustness of the methods; and (ii) leverage a customized version of FSL to (a) remove the need of application-specific feature extraction; and (b) help generalize to new environments by only leveraging a limited number of new samples.

Solution

• The solution relates to a novel framework for robust and environment-independent Wi-Fi sensing (ReWiS).
• ReWiS addresses these issues by leveraging multi-antenna, multi-receiver diversity and fine-grained frequency resolution. It employs few-shot learning (FSL) for reduced data collection requirements and rapid task generalization with few samples, alongside SVD for consistent FSL input.
• It ensures robust, environment-independent Wi-Fi sensing with enhanced accuracy and lower computational demands.
• ReWiS framework includes multi-antenna, multi-receiver diversity, and fine-grained frequency resolution.
• Leverages spatial, temporal, and frequency diversity to enhance sensing robustness.

Application

• Wi-Fi sensing for applications like human activity recognition, remote health monitoring, and surveillance.
• ReWiS’s methodology can be extended beyond Wi-Fi to other wireless technologies for spatial diversity and enhanced robustness in sensing operations. Its generalization capabilities make it applicable in various scenarios such as smart homes, device-free surveillance, and indoor localization.

Comment

• It reduces the cost of data acquisition and labeling by adopting customized ProtoNet to learn and generalize with limited data.
• It reduces the complexity of the learning method and data pre-processing while maintaining the accuracy by collecting data over multiple antennas, multiple receivers at different locations and high-resolution CSI data over large channel bandwidth. 

Wireless sensing resource coordination method and apparatus, and storage medium

WO Patent: WO2022077274A1

Publication Date: 2022-04-21

Assignee: Beijing Xiaomi Mobile Software Co Ltd

This efficiency enhances device communication, particularly in WLAN sensing applications like location discovery, proximity, and presence detection.

The wireless sensing resource frame includes wireless sensing information, and the wireless sensing information is used for coordinating the station to send the wireless sensing request frame.

Solution

• The solution relates to coordinating wireless sensing resources among multiple APs to address problems like potential interference and inefficiency in wireless communication.
• Determining and sending a radio sensing resource frame with specific duration and capability information to streamline communication, avoid interference, and match station and AP capabilities for effective WLAN sensing.
• The wireless sensing resource coordination method provided reduces interference to other devices by coordinating APs to streamline the communication process.
• The method facilitates accurate and efficient initiation and response of WLAN sensing, avoiding communication conflicts, and ensuring precise timing and security in data exchange.

Application

• WLAN sensing, specifically in application scenarios such as location discovery in dense scenarios, proximity detection, and presence detection.
• Beyond its application in WLAN sensing, this method has potential for use in any field requiring precise wireless coordination and communication including IoT devices, smart home technologies, vehicular communication systems, and other densely networked environments.

Comment

The solution is suitable for coordinating and controlling the wireless sensing resources of multiple APs when there are multiple APs responding to the wireless sensing initiated by the station at the same time.

Multi-user physical layer packet for sensing

US Patent: US2023268975A1

Publication Date : 2023-08-24

Assignee: Telefonaktiebolaget LM Ericsson (publ)

Spatial multiplexing of sensing and non-sensing devices is enabled, while, compared to single user (SU) transmissions, sensing performance is not (or only slightly) degraded and/or inter-stream interference experienced by the non-sensing device(s) is not (or only slightly) increased.

Disturbance to both sensing and non-sensing devices by transmissions to the other type is reduced compared to other approaches for provision of multi-user physical layer packets.

Solution

• The solution relates to the problems associated with spatial multiplexing of sensing and non-sensing devices.
• Transmitter is configured to transmit more than one spatially multiplexed streams comprised in a multi-user physical layer packet for a plurality of users.
• A method for a first type user (sensing device) and a method for a second type user (non-sensing device) involve coordinated operations to enhance WLAN sensing and data reception capabilities with controlled interference and improved spatial multiplexing efficiency.
• This includes leaving a data field empty for sensing operations, controlling emission strength to reduce interference, and applying specific transmitter configurations for different streams.

Application

• The invention is intended for use in wireless local area network (WLAN) sensing, specifically under the standardization of IEEE 802.11, enabling enhanced WLAN sensing operations within license-exempt frequency bands between 1 GHz and 7.125 GHz and above 45 GHz.
• The solution can be equally applicable in other contexts, e.g., sensing within a context of Third Generation Partnership Project (3GPP) standards.

Comment

The solution is suitable for overcoming the problems associated with spatial multiplexing of sensing and non-sensing devices.

Multi-target activity sensing method and system

CN Patent: CN115022804A

Publication Date:  2022-09-06

Assignee: Shanghai Wuqi Microelectronics Co Ltd

Improves the practicability of Wi-Fi network perception and enlarges the application range of Wi-Fi network perception technology by enabling activity detection of multiple moving targets indoors, through beam scanning and OFDMA distribution in Wi-Fi networks.

Solution

• The solution relates to the identification of individual activities among multiple people moving in a room.
• A multi-target activity sensing method and system that allows for the sensing of activities of multiple people indoors by transmitting directional beams in parallel to the direction of moving targets, calculating channel characteristic change values, and using artificial intelligence to perform activity perception on each target.
• The system includes a signal transmitting device and an activity detecting device, utilizing directional beams, specified number of resource units, and antenna weight sequence functions to identify and perceive activities of multiple targets. It employs interference beam suppression for concurrent signal clarity.

Application

Various environments requiring indoor multi-person activity detection and monitoring, such as smart homes, security, healthcare monitoring, and automated control systems.

Comment

• The solution relates to multi-target activity sensing method, which can realize the sensing of activities of multiple people indoors.
•  Communication technology, specifically for enhancing multi-target activity sensing using Wi-Fi networks.

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Explore Part 1: Wi-Fi Sensing Technology: Applications, Challenges & Key Players