Clock Source Sharing for GNSS Mobile Power Savings
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Solution Overview
Problem
GNSS enabled mobile devices face challenges in power conservation as they require continuous operation of both local and host clocks, leading to increased power consumption, especially when switching between GNSS active and inactive modes.
Innovation Solution
Implementing a method and system that allows GNSS enabled mobile devices to selectively share a clock source between a local GNSS clock and a host clock, turning off the unused clock to conserve power. In GNSS active mode, the local GNSS clock is used for GNSS operations, while in GNSS inactive mode, the host clock is used for non-GNSS radios, thereby optimizing power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both local GNSS clock and host clock are continuously operated to support GNSS and non-GNSS radios, then reliable timekeeping and radio operations are ensured, but power consumption increases
Solution Approach 1:
The patent merges the functions of the local GNSS clock and host clock by allowing them to share a single crystal oscillator resource. The system dynamically switches between using the local clock for GNSS operations and the host clock for non-GNSS operations, eliminating the need for two separate continuous clock sources while maintaining both functionalities.
Solution Approach 2:
The system implements dynamic clock source selection based on operational mode. A clock source manager continuously monitors whether the GNSS radio is active or inactive and switches the crystal oscillator assignment accordingly: assigning it to the local GNSS clock during GNSS active mode, and to the host clock during GNSS inactive mode, thereby optimizing power consumption in real-time.
2Adaptability or versatility
If two separate clocks are maintained for GNSS and non-GNSS operations, then operational versatility is ensured, but device complexity increases
Solution Approach 1:
The patent implements a universal crystal oscillator that serves multiple functions depending on the operational context. The same physical oscillator resource is universally applied to both GNSS clock operations and host clock operations, with a clock source manager that handles the functional switching. This eliminates the need for separate dedicated oscillators while maintaining full operational versatility.
3Use of energy by moving object
If the host clock is turned off during GNSS active mode to save power, then power consumption is reduced, but clock switching complexity increases
Solution Approach 1:
The patent introduces a clock source manager as an intermediary component that handles the complexity of clock source selection and switching. This mediator monitors the GNSS radio operational state and automatically assigns the crystal oscillator to the appropriate clock (local GNSS clock or host clock), isolating the switching logic from the rest of the system and managing the complexity centrally.
Data Source
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AI summary
A GNSS enabled mobile device selects an associated local GNSS clock or host clock as a clock source to operate a GNSS radio and one or more non-GNSS radios within the GNSS enabled mobile device. When the GNSS radio is in a GNSS active mode, the local GNSS clock is turned ON and selected to be shared with the host. The host operates the GNSS radio and the non-GNSS radios only using the local GNSS clock instead of the host clock. The host clock is turned OFF to save power. When the GNSS radio is in a GNSS inactive mode, the host clock is turned ON and selected to operate the non-GNSS radios. The local GNSS clock is turned OFF to save power. The non-GNSS radios comprise a Bluetooth radio, a WiFi radio, a FM radio, a cellular radio and/or a WiMAX radio.