Wireless Frame Retransmission Control via Explicit NACK Feedback

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Solution Overview

Problem

Conventional wireless transmission protocols waste power resources by retransmitting frames that have already been correctly received at the receiver, particularly in miniaturized devices like the digital plaster, due to the possibility of duplicate frame transmission.

Innovation Solution

Modifying the DLL protocol to ensure frames are only retransmitted after an explicit NACK is received, with the receiver repeating ACK/NACK transmissions until the expected frame is received, and the sender waiting for a response before sending the next frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sender retransmits frames upon timeout without receiving ACK/NACK, then reliability is improved, but power consumption increases due to unnecessary retransmissions of correctly received frames

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention implements a feedback mechanism where the receiver actively sends ACK/NACK responses to the sender. The sender only retransmits frames when it receives an explicit NACK, rather than retransmitting on timeout. This feedback loop prevents unnecessary retransmissions of correctly received frames, reducing power consumption while maintaining transmission reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention inverts the conventional timeout-based retransmission approach. Instead of the sender retransmitting when no response is received, the receiver explicitly tells the sender whether to retransmit by sending ACK (don't retransmit) or NACK (retransmit). This inversion eliminates ambiguous timeout scenarios and prevents unnecessary retransmissions.

Inventive Principle:
Principle #13The other way round (Inversion)

2Measurement precision

If the receiver waits for ACK/NACK before processing next data, then transmission accuracy is improved, but communication efficiency deteriorates due to idle waiting time

Engineering Contradiction:
Improvetransmission accuracyVSAvoidcommunication efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The receiver performs preliminary actions by sending ACK/NACK responses as soon as frame validation is complete, without waiting for the sender's timeout period. This allows the sender to immediately know whether to retransmit or proceed, eliminating idle waiting time and improving communication efficiency while maintaining accuracy through explicit validation feedback.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2201715B1Wireless transmission method and apparatus
Publication Date: 2013.06.19 TOUMAZ TECH
  • EP2201715B1 patent drawingFigure 1
  • EP2201715B1 patent drawingFigure 2
  • EP2201715B1 patent drawingFigure 3

AI summary

A method of transmitting a data sequence between a sender and a receiver over a wireless link. The method comprises, at the sender, segmenting the data sequence into a plurality of data segments and, for each segment, constructing a frame containing as payload the data segment, transmitting the frame across the wireless link, and receiving an acknowledgement or non- acknowledgement from said receiver for the frame, and only upon receipt of such acknowledgement or non-acknowledgement, retransmitting the frame or transmitting a further frame containing as payload the next data segment.