Fine Timing Measurement Burst Offset for RTT Accuracy
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Solution Overview
Problem
Current satellite positioning systems face challenges in accurately measuring round trip time (RTT) between wireless stations in dense environments, leading to increased congestion and measurement errors, especially in indoor settings where traditional techniques require multiple messages and synchronized clocks, increasing power consumption and latency.
Innovation Solution
The method involves transmitting a fine timing measurement (FTM) request message with a specified minimum time offset between initial and subsequent messages, allowing for burst transmissions that reduce the number of messages needed to measure RTT, thereby minimizing errors and congestion, and using a Burst Offset field to synchronize clocks without the need for precise timing synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional RTT measurement techniques are used with multiple messages and synchronized clocks, then measurement accuracy is improved, but power consumption and latency increase
Solution Approach 1:
The patent segments the RTT measurement process into two distinct phases: a calibration phase for clock synchronization and a measurement phase for RTT acquisition. This segmentation allows the system to perform precise clock calibration once, and then use that calibration for multiple subsequent RTT measurements without re-synchronizing, thereby reducing power consumption while maintaining measurement accuracy.
Solution Approach 2:
The patent performs clock calibration as a preliminary action before RTT measurements. By pre-synchronizing the clocks between wireless stations through the calibration phase, the system eliminates the need for continuous synchronization during measurement operations, reducing ongoing power consumption while ensuring accurate timing for RTT calculations.
2Measurement precision
If traditional RTT measurement techniques are used with multiple messages and synchronized clocks, then measurement accuracy is improved, but latency increases
Solution Approach 1:
The patent segments the RTT measurement process into a one-time calibration phase and subsequent measurement phases. This allows the system to perform necessary clock synchronization upfront, and then conduct rapid RTT measurements without repeated synchronization overhead, thereby reducing latency while maintaining measurement precision.
Solution Approach 2:
By performing clock calibration as a preliminary action before measurements, the system establishes accurate timing references in advance. This eliminates the need for time-consuming synchronization procedures during each measurement cycle, significantly reducing latency while preserving RTT measurement accuracy.
3Measurement precision
If multiple messages are transmitted for RTT measurement, then measurement accuracy is improved, but congestion increases
Solution Approach 1:
The patent segments message transmission into a calibration phase and measurement phase. The calibration phase establishes timing relationships, enabling the measurement phase to use fewer messages for RTT acquisition. This reduces overall message traffic and congestion while maintaining measurement accuracy through the prior calibration.
Solution Approach 2:
By performing clock calibration as a preliminary action, the system establishes accurate timing references that enable subsequent RTT measurements to be performed with fewer message exchanges. This reduces message traffic and network congestion while preserving measurement precision.
4Measurement precision
If precise clock synchronization is implemented, then RTT measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments clock synchronization into a dedicated calibration phase that occurs separately from the measurement phase. This calibration phase handles the complexity of clock synchronization once, allowing subsequent measurements to proceed with simpler timing operations, thereby reducing overall device complexity while maintaining measurement accuracy.
Solution Approach 2:
By performing clock calibration as a preliminary action before measurements, the patent consolidates the complex synchronization operations into a single upfront phase. This eliminates the need for continuous complex synchronization mechanisms during measurements, reducing device complexity while ensuring accurate RTT measurements through the pre-established timing references.
Data Source
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AI summary
Disclosed are methods and systems for obtaining measurements of a range between devices in an exchange messages. In particular, described are techniques for transmitting messages between or among devices to share computed parameters indicative of ranges between devices. In particular implementations, shared computed parameters indicative of ranges between or among devices may enable computation of estimated locations of one or more of devices.