RFID Reader Channel State Detection via Carrier Sensing

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Solution Overview

Problem

Existing readers cannot determine the state of a channel while not communicating with a wireless tag, which hinders efficient channel selection and communication.

Innovation Solution

A reader equipped with an antenna and a processor that measures radio wave intensity on predetermined channels during carrier sensing times, storing channel reports to indicate channel availability and intensity values, and outputs warnings or error messages as necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the reader does not measure radio wave intensity during carrier sensing time, then the device complexity is reduced, but the ability to determine channel state is lost

Engineering Contradiction:
Improvechannel state determinationVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The reader utilizes its existing antenna and processor to perform carrier sensing and measure radio wave intensity during carrier sensing time. The system serves itself by using the same hardware components for both communication and channel state detection, eliminating the need for additional dedicated measurement devices.

Inventive Principle:
Principle #25Self-service

2Reliability

If the reader monitors channel state during carrier sensing time, then the reliability of communication is improved, but the loss of time for data acquisition increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidtime for data acquisition
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The reader performs carrier sensing and measures radio wave intensity in advance during carrier sensing time before actual communication begins. By detecting channel state beforehand, the system ensures reliable communication selection while the measurement occurs during a time when no data acquisition is happening, thus not extending the actual communication duration.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the reader selects channels without determining their state, then the productivity is improved, but the harmful factors from interference increase

Engineering Contradiction:
Improvechannel selection speedVSAvoidinterference from other devices
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The reader measures radio wave intensity on each channel during carrier sensing time and uses this feedback information to determine channel state. The system stores channel reports indicating which channels are occupied and selects communication channels based on this feedback, thereby avoiding interference while maintaining efficient channel selection.

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

Enables the reader to determine channel state and select available channels for communication, preventing interference and ensuring reliable data acquisition from wireless tags.

Implementation Method 1

an antenna (13) for communicating with a wireless tag; a processor (111) configured to measure a time when a radio wave is received on a predetermined channel

Methodology Applied
Scientific EffectElectromagnetic radiation reception: Electromagnetic Induction

Data Source

PatentEP3872682B1Reader and method of operating a reader
Publication Date: 2023.11.15 TOSHIBA TEC KK
  • EP3872682B1 patent drawingFigure 1
  • EP3872682B1 patent drawingFigure 2~3
  • EP3872682B1 patent drawingFigure 4

AI summary

A reader includes an antenna, a processor, and a memory storage. The antenna communicates with a wireless tag. The processor measures a time when a radio wave is received on a predetermined channel during a carrier sensing time, the carrier sensing time being a time when the wireless tag is not communicating. The memory storage stores a channel report indicating the time.