Wireless Device State Management with RF Energy Harvesting

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Solution Overview

Problem

Wireless devices that rely on harvested RF energy face challenges in saving and restoring state information due to unpredictable and variable power availability, as the energy costs for these operations can exceed the available power, especially when transitioning between active and low-power modes.

Innovation Solution

A method and apparatus for a wireless device that includes an energy harvester, processors, and memory to store and restore state information, where the device determines available power and selectively restores operations based on that power, allowing for flexible saving and restoring of state information to conserve energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wireless device saves and restores all state information, then the device can fully restore operational state, but the power consumption exceeds available harvested power

Engineering Contradiction:

Improvestate restoration completenessVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments state information into multiple categories (e.g., critical state information, non-critical state information) and selectively restores only the necessary portions based on available power. This allows the system to divide the restoration task into manageable parts that can be executed within power constraints while maintaining essential functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements partial restoration by selecting and restoring only a subset of state information rather than all state information. The system determines the minimum necessary state data required for basic operation and restores only that portion, accepting that some non-essential state may be lost to ensure operation within available power limits.

Inventive Principle:

Principle #16Partial or excessive action

2Duration of action of moving object

If the wireless device enters low-power mode to conserve energy, then battery life is extended, but the device loses operational state and requires power-intensive restoration

Engineering Contradiction:

Improvebattery lifeVSAvoidrestoration power cost

Core Design Contradiction:

Duration of action of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary actions by maintaining certain state information in volatile memory during low-power mode rather than completely saving to non-volatile memory. This preliminary preservation of state allows for faster, lower-power restoration when exiting low-power mode, reducing the power cost of state recovery while still achieving significant power savings during idle periods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the power mode parameters dynamically based on available harvested power. When power is available, the system operates in full-power mode with complete state restoration. When harvested power is limited, the system transitions to low-power mode with selective state restoration, adjusting operational parameters to match available energy resources.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the wireless device relies on harvested RF energy, then mobility and battery-free operation are achieved, but power availability becomes unpredictable and variable

Engineering Contradiction:

Improvepower source flexibilityVSAvoidpower availability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic power management that continuously adapts to changing harvested power conditions. The system monitors available power in real-time and dynamically adjusts its operation mode, state saving frequency, and restoration scope accordingly. This dynamic adaptation allows reliable operation despite unpredictable power availability from RF harvesting.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent incorporates feedback mechanisms that monitor harvested power levels and use this information to control state management operations. The system receives feedback about available power and adjusts its behavior (saving state more frequently when power is abundant, reducing restoration scope when power is scarce) to maintain reliable operation under varying power conditions.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables efficient power management by adapting the save and restore operations to the available power, ensuring the wireless device can maintain functionality while minimizing energy consumption, even with variable power sources.

Implementation Method 1

one or more energy harvesters configured to convert radio-frequency energy into power for the wireless device

Methodology Applied

Scientific EffectElectromagnetic energy harvesting: Electromagnetic Induction

Data Source

PatentUS11237910B2Method and apparatus for saving and restoring state information

Publication Date: 2022.02.01 ATMOSIC TECHNOLOGIES INC

AI summary

This disclosure provides a method and apparatus for saving and restoring state information of a wireless device with varying amounts of available power, such as wireless devices that may harvest power from radio-frequency signals. The wireless device may save and restore varying amounts of state information based at least in part on the amount of power available. In some embodiments, some of the stored state information may be lost as the available power decreases.