Fine Timing Measurement Exchange for Indoor RTT Accuracy
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Solution Overview
Problem
Current methods for determining precise location of devices in indoor environments using satellite positioning systems are limited by inaccuracies in measuring round trip time (RTT) due to timing errors and require multiple message exchanges, which can be inefficient.
Innovation Solution
The method involves an initiating wireless station transmitting a fine timing measurement request message to a responding station, allowing for the computation and sharing of RTT-based range parameters, enabling more accurate and efficient range measurements through fewer message exchanges using fine timing measurement (FTM) request and response messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional RTT measurement methods are used, then location determination can be performed, but measurement accuracy is reduced due to timing errors and multiple message exchanges are required
Solution Approach 1:
The patent applies preliminary action by having the initiating STA share its ranging parameters (such as timing reference information) with the responding STA before the actual RTT measurement takes place. This pre-sharing of parameters enables the responding STA to perform more accurate timing measurements without requiring multiple iterative message exchanges, thus improving measurement accuracy while reducing communication overhead
Solution Approach 2:
The patent implements feedback by having the initiating STA transmit computed range parameters back to the responding STA based on the FTM messages received. This feedback mechanism allows both stations to refine their timing measurements and achieve higher accuracy in a single exchange rather than requiring multiple iterative measurements
2Measurement precision
If multiple message exchanges are performed for accurate RTT measurement, then measurement accuracy improves, but time consumption and operational complexity increase
Solution Approach 1:
By performing the parameter sharing action beforehand, the patent eliminates the need for multiple iterative message exchanges that would otherwise be required to establish timing references. The initiating STA prepares and transmits its ranging parameters in advance, allowing the responding STA to immediately perform accurate timing measurements upon receiving FTM messages, thus reducing overall time consumption
Solution Approach 2:
The patent changes the parameter exchange approach by having the initiating STA actively share its ranging parameters (such as timing reference values) with the responding STA. This parameter change enables the responding STA to perform more accurate measurements with fewer message exchanges, directly reducing the time loss associated with multiple iterations
Data Source
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AI summary
Disclosed are methods and systems for obtaining measurements of a range between devices based on a Round Trip Time (RTT) for an exchange messages. In particular, described are techniques for transmitting messages between or among devices to share computed parameters indicative of ranges between devices.