LPP Positioning Session Early Fix Handling
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Solution Overview
Problem
Current positioning technologies, such as those using the Long Term Evolution (LTE) positioning protocol (LPP), face challenges in obtaining accurate and timely position fixes for mobile devices, especially in indoor environments where satellite signals are weak or unavailable, leading to delays in location estimation and emergency services.
Innovation Solution
Implementing a method where mobile devices receive timer values for early and final response timeouts during positioning sessions, allowing for an initial partial position fix to be transmitted before the final timeout, with subsequent messages providing additional location parameters once available, dynamically adjusting to the device's signal environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the mobile device waits for the final timeout to provide the complete position fix, then the positioning accuracy is improved, but the positioning time is increased
Solution Approach 1:
The position fix parameters are segmented into two groups: essential parameters that can be determined early and supplementary parameters that require more time. The mobile device transmits the essential parameters at the early timeout to provide a preliminary position fix, and transmits the supplementary parameters at the final timeout to refine the position accuracy. This segmentation resolves the contradiction by delivering usable positioning information quickly while maintaining the option for higher accuracy.
Solution Approach 2:
The mobile device performs preliminary positioning calculations using available parameters before the final timeout expires. By preparing and transmitting the initial position fix at the early timeout, the device enables the location server to begin processing location information earlier, reducing overall positioning time while preserving the ability to improve accuracy with additional measurements.
2Loss of time
If the mobile device transmits an initial partial position fix before the final timeout, then the positioning time is reduced, but the positioning accuracy is compromised
Solution Approach 1:
The system implements feedback through multiple response messages. The initial response message at early timeout provides a preliminary position fix, and the final response message at final timeout provides corrections or supplements to improve accuracy. The location server can use the initial position fix immediately while incorporating the final message to refine the result, thus reducing perceived positioning time without permanently compromising accuracy.
Solution Approach 2:
The mobile device transmits a partial position fix with essential parameters at the early timeout, which is sufficient for many positioning applications. This partial action provides timely positioning information without requiring complete measurements, and the system can accept that some applications may not need the full accuracy that would require waiting for all measurements.
3Measurement precision
If the mobile device requests and processes additional location parameters, then the positioning accuracy is improved, but the device complexity increases
Solution Approach 1:
The positioning system dynamically adapts to signal conditions by selectively requesting and processing parameters. When signal conditions are good, the device can acquire additional parameters like OTDOA measurements to improve accuracy. When conditions are poor, the device falls back to using only available parameters like GPS or cell ID, reducing processing complexity while maintaining acceptable positioning performance.
Data Source
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AI summary
Example methods, apparatuses, and/or articles of manufacture are disclosed herein that may be utilized, in whole or in part, to facilitate and/or support one or more operations and/or techniques for handling an early position fix for LPP-type positioning sessions, such as for use in or with mobile communication devices, for example.