RFID Tag Binding Handle for Multi-Reader Communication

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Solution Overview

Problem

The Gen2V2 protocol-based RFID systems face communication loss issues due to receiving ACK commands with incorrect session handles, particularly in scenarios where tags are simultaneously within the read zones of multiple readers.

Innovation Solution

A method is introduced that includes an inventory initiating command and access initiating command, which generate binding handles incorporating a reader identifier, allowing tags to differentiate between correct and incorrect ACK commands and maintain communication with the intended reader.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If tags are simultaneously within the read zones of multiple readers using Gen2V2 protocol, then the system can serve multiple readers, but communication loss occurs due to receiving ACK commands with incorrect session handles

Engineering Contradiction:

Improveability to serve multiple readersVSAvoidcommunication reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The session handle is segmented into two parts: a reader identifier portion and a tag-specific portion. This segmentation allows the tag to distinguish between ACK commands from different readers, preventing communication loss while maintaining the ability to serve multiple readers simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The tag incorporates feedback mechanisms by including the reader identifier in the session handle. This enables the tag to verify whether an received ACK command is intended for it and from the correct reader, thereby maintaining reliable communication in multi-reader environments.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If the tag transitions to Arbitrate state upon receiving incorrect ACK commands, then the tag follows protocol specifications, but unnecessary communication interruptions occur

Engineering Contradiction:

Improveprotocol complianceVSAvoidcommunication interruption time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The tag performs preliminary verification of the reader identifier in the session handle before transitioning to the Arbitrate state. This preliminary action prevents unnecessary state transitions and communication interruptions while maintaining protocol compliance for genuine protocol violations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The reader identifier acts as an intermediary verification element between the ACK command and the tag's state transition. This intermediary check prevents premature transitions to Arbitrate state caused by incorrect ACK commands from other readers.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If the session handle contains only random numbers without reader identification, then the protocol remains simple, but the tag cannot differentiate between ACK commands from different readers

Engineering Contradiction:

Improvesession handle structureVSAvoidreader identification information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The session handle merges two elements: the reader identifier and the tag-specific random portion. This combination maintains relative protocol simplicity while embedding necessary reader identification information to enable differentiation between ACK commands from different readers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The session handle serves multiple functions: it acts as both an acknowledgment token and a reader identification carrier. This multi-functionality eliminates the need for separate identification mechanisms, maintaining protocol simplicity while enabling reader differentiation.

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

This approach prevents unnecessary transitions to the Arbitrate state, ensuring continuous communication between tags and readers by correctly identifying and acknowledging commands from the intended reader, thereby reducing communication loss.

Implementation Method 1

Such a tag relies purely on backscatter communication

Methodology Applied

Scientific EffectBackscatter communication:

Data Source

PatentEP3333755B1Method for providing identification and access with respect to a radio-frequency tag

Publication Date: 2019.10.30 EM MICROELECTRONIC-MARIN

Figure 1

AI summary

The method relates to a method for providing identification and access with respect to a passive radio-frequency tag (Tag 3) in a tag population (Tags 1-5), the passive tag (Tag 3) being configured for receiving ACK commands comprising an identification parameter in the form of a 16-bit number, said method comprising the following steps: - receiving a command for initiating an inventory round or a command for initiating a tag access, said command comprising, as a parameter, a number comprising an identifier of a reader (Reader A) - generating a 16-bit value referred to as first or second binding handle, said first or second binding handle comprising N juxtaposed bits forming the reader identifier - backscattering said first or second binding handle - receiving an ACK command - analyzing the identification parameter of said ACK command, and in a case where said identification parameter comprises the reader identifier then ignoring said ACK command.