Passive RFID Protocol Management for Multi-Reader Power Interruption

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Solution Overview

Problem

Existing passive RFID transponders fail to manage communication protocols effectively when multiple readers provide interrogation fields simultaneously, leading to incomplete power-down states and protocol interruptions, which can result in intermediate protocol states and data security issues.

Innovation Solution

A protocol management method for passive RFID devices that includes field detectors for each interrogation field, allowing the device to enter a Standby state when power levels are maintained, and automatically restart communication protocols upon field re-detection, eliminating the need for a Power-On Reset (POR) signal and ensuring proper re-initialization and reconfiguration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the transponder is powered by multiple readers simultaneously, then power availability is improved, but protocol state management deteriorates due to incomplete power-down states

Engineering Contradiction:
Improvepower availabilityVSAvoidprotocol state management
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent segments the power management by introducing a protocol-specific power-down concept. Each communication protocol (UHF, LF-HF) has its own power-down state that is independently managed. When one protocol needs to power down, it does so even if other protocols remain active and powered by other readers. This segmentation allows reliable protocol state management while maintaining power availability from multiple readers.

Inventive Principle:
Principle #1Segmentation

2Duration of action of stationary object

If the transponder remains powered during field interruption, then power continuity is improved, but protocol completion deteriorates due to indefinite intermediate states

Engineering Contradiction:
Improvepower continuityVSAvoidprotocol completion
Core Design Contradiction:
Duration of action of stationary objectVSProductivity

Solution Approach 1:

The patent introduces dynamic state transitions for each protocol based on field detection. The field detectors continuously monitor the presence of interrogation fields and dynamically trigger power-down transitions when fields are interrupted. This dynamic approach ensures that protocols complete properly when fields are interrupted, while the system remains flexible to resume operations when fields return, maintaining both power continuity and protocol completion.

Inventive Principle:
Principle #15Dynamics

3Reliability

If field detectors continuously monitor interrogation fields, then protocol interruption detection is improved, but device complexity increases

Engineering Contradiction:
Improveprotocol interruption detectionVSAvoiddetector circuitry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements multi-functional field detectors that serve multiple purposes. The same field detectors used for initial protocol activation are also used for continuous monitoring during protocol execution. This universal use of field detectors eliminates the need for separate monitoring circuits, reducing overall device complexity while maintaining reliable protocol interruption detection throughout the communication process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Prevents communication protocols from remaining in indefinite or intermediate states due to interrupted field reception, ensuring secure data handling and efficient protocol restarts without POR signal dependency, thereby maintaining data integrity and operational efficiency.

Implementation Method 1

a passive RF identification device (RFID) which is arranged for harvesting power from at least a first reader sending a first interrogation field at a first frequency and from an independent second reader sending a second interrogation field at a second frequency different from the first frequency

Methodology Applied
Scientific EffectElectromagnetic energy harvesting: Electromagnetic Induction

Data Source

PatentEP3079104B1Protocol management method for a passive RF identification device which can harvest power from different power sources
Publication Date: 2018.01.10 EM MICROELECTRONIC-MARIN
  • EP3079104B1 patent drawingFigure 1
  • EP3079104B1 patent drawingFigure 2

AI summary

The protocol management method concerns a passive RF identification device which comprises a first field detector for a first interrogation field and a second field detector for a second interrogation field in order to watch for the reception of these first or second interrogation fields at least respectively during executions of corresponding first and second communication protocols. If during the execution of a communication protocol the reception of the corresponding interrogation field is no more detected by the corresponding field detector while the power provided by the power generator remains equal or superior to the requested power level, then this communication protocol is stopped and the identification device enters a Standby state. When the identification device is in this Standby state, the corresponding field detector continues to watch for the reception of the corresponding interrogation field in order to detect if it is again received and, if this is the case, to trigger a restart of this corresponding communication protocol.