Wi-Fi Sensing Time Synchronization for Unassociated Stations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Wi-Fi sensing systems face challenges in synchronizing time across unassociated stations, which affects the accuracy and efficiency of applications such as motion detection and tracking.
Innovation Solution
A method for time synchronization in Wi-Fi sensing systems involves obtaining timing information from an unassociated access point, generating local timing information, and transmitting a transmission response with updated timestamps, using frames like sensing measurement setup requests and CTS-to-self frames to synchronize local timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If unassociated stations perform sensing transmissions without time synchronization, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the sensing transmitter receives timing information from unassociated access points and adjusts its local timing information accordingly. The transmitter sends sensing transmissions with timestamps based on updated local timing information, enabling precise time synchronization without requiring complex synchronization protocols. This feedback loop allows unassociated stations to maintain accurate timing for sensing measurements.
2Measurement precision
If timing information is obtained from multiple unassociated access points, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent applies preliminary action by having unassociated access points broadcast timing information in advance (e.g., in beacon frames or probe responses). The sensing transmitter can obtain and process this timing information before actual sensing transmissions occur, reducing the time delay. The transmitter maintains local timing information that is periodically updated based on received timing information from multiple access points.
3Measurement precision
If local timing information is continuously updated, then measurement precision is improved, but use of energy increases
Solution Approach 1:
The patent implements periodic action by having the sensing transmitter obtain timing information from unassociated access points at regular intervals rather than continuously. The local timing information is updated periodically based on received timing information, allowing the system to maintain synchronization accuracy while reducing energy consumption compared to continuous updates. The resynchronization timer mechanism enables periodic refreshing of timing information.
Data Source
AI summary
Systems and methods for Wi-Fi sensing by networking devices are provided. A sensing transmitter is configured to obtain timing information from an unassociated access point The sending transmitter is further configured to generate local timing information, according to the timing information and to receive a transmission request from the unassociated access point, the transmission request including a timing information update. The timing information update is used to update the local timing information. A transmission response including a timestamp based on updated local timing information is sent responsive to a transmission request.