GPS Out-of-Range Detection for Mobile Power Conservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile devices with GPS receivers face high power consumption and battery drain when continuously searching for satellite signals in areas with poor coverage, such as indoors, as they attempt to maintain or regain a lock, which is inefficient and unsustainable.
Innovation Solution
Implementing a method to determine if a mobile device is out of range of a position broadcast system by measuring signal strengths from satellites and defining out-of-range criteria, allowing the device to stop searching for signals and conserve power when these criteria are met, and optionally restarting the search after a predetermined period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the GPS receiver continuously searches for satellite signals, then the device can maintain or regain position lock, but power consumption increases dramatically
Solution Approach 1:
The patent implements periodic searching instead of continuous searching by establishing search intervals based on device motion detection. When the device is determined to be stationary, the GPS receiver enters a low-power state and only periodically attempts to reacquire satellite signals, rather than continuously searching. This periodic approach maintains position lock reliability while dramatically reducing power consumption during stationary periods.
Solution Approach 2:
The patent dynamically adjusts the GPS receiver's operating state based on device motion status. When motion is detected, the system transitions to active continuous searching mode to quickly reacquire satellites. When the device is stationary, it transitions to a low-power periodic searching mode. This dynamic adaptation allows the system to optimize between reliability and power consumption based on real-time conditions.
2Reliability
If the GPS receiver searches for satellites in areas with poor coverage, then position information can be obtained, but battery life is significantly reduced
Solution Approach 1:
The patent employs acceleration sensors and other device resources to self-detect when the device is stationary or in areas with poor satellite coverage. Based on this self-detected information, the system automatically adjusts GPS searching behavior without requiring external intervention. This self-service approach prevents futile continuous searching in poor coverage areas, thereby preserving battery life while maintaining position information acquisition capability when conditions improve.
Solution Approach 2:
In areas with poor satellite coverage, the system implements periodic searching attempts rather than continuous searching. The GPS receiver periodically wakes from a low-power state to check for available satellites, then returns to sleep mode. This periodic action reduces battery consumption significantly compared to continuous searching, while still allowing the device to acquire position information when satellites become available.
3Reliability
If the device attempts to lock onto satellites while inside a building, then position information may be obtained temporarily, but power is wasted on futile searches
Solution Approach 1:
The patent introduces acceleration sensors and motion detection mechanisms as intermediary systems that monitor device context and provide information to the GPS controller. These intermediary sensors detect when the device is stationary or likely inside a building, and this information mediates the GPS receiver's searching behavior. The intermediary system enables the GPS to reduce or pause searching in situations where position lock is unlikely to be achieved, preventing energy waste while preserving the ability to lock when conditions are favorable.
Solution Approach 2:
The system implements feedback loops where the GPS receiver's performance and device motion status continuously inform searching behavior. When the device is stationary or acceleration sensors indicate indoor conditions, the system provides feedback to reduce searching intensity. When motion is detected or satellite signals are successfully acquired, feedback triggers resumption of active searching. This feedback mechanism ensures energy is not wasted on futile searches while maintaining position lock capability when possible.
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A method and a mobile device configured to obtain position information from a position broadcast system, the position broadcast system comprising a plurality of transmitters that each broadcast a respective signal containing position information for the respective transmitter. The method comprising: measuring signal strengths of signals from a plurality of the transmitters of the position broadcast system; and determining that the mobile device is out of range of the position broadcast system if the measured signals strengths satisfy at least one out of range criterion.