Broadcast Network Coding Feedback for Decodability Threshold Control

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Solution Overview

Problem

In wireless communications, the lack of feedback in broadcasting network encoded packets leads to inefficient packet transmission, resulting in resource wastage and unnecessary duplication, as transmitters continue to broadcast packets without knowing which ones have been successfully decoded by receivers.

Innovation Solution

Implementing a feedback design system where receivers provide feedback on the number of successfully received network encoded packets to the transmitter, allowing the transmitter to determine if the decodability threshold is met and adjust transmission accordingly, thereby optimizing packet broadcasting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the transmitter repeatedly broadcasts packets blindly without feedback, then the transmission can be simple and fast, but resource wastage increases and reliability decreases

Engineering Contradiction:
Improvetransmission speedVSAvoidresource wastage
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent implements a feedback mechanism where receivers send acknowledgment bits to the transmitter indicating which packets have been successfully decoded. This feedback allows the transmitter to adjust retransmission strategies, avoiding unnecessary repeated broadcasts of already received packets while ensuring reliable delivery to all receivers.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the transmitter broadcasts packets without knowing decoding status, then device complexity is reduced, but reliability of packet delivery deteriorates

Engineering Contradiction:
Improvetransmitter complexityVSAvoidpacket delivery reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The feedback mechanism provides the transmitter with decoding status information from receivers, enabling reliable packet delivery determination. The transmitter can identify when all receivers have successfully decoded packets and terminate transmission accordingly, ensuring reliability without requiring complex tracking of individual receiver states.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Receivers autonomously determine their own decoding status and generate feedback information. This self-service approach allows receivers to independently assess which packets they have successfully decoded and report this information, reducing the burden on the transmitter to track and manage individual receiver states.

Inventive Principle:
Principle #25Self-service

3Reliability

If feedback is implemented to track packet reception, then reliability improves, but signaling overhead increases

Engineering Contradiction:
Improvepacket delivery reliabilityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential feedback information needed for termination decisions - specifically, acknowledgment bits indicating whether packets have been successfully decoded. By taking out only this critical information rather than transmitting complete reception status reports, the signaling overhead is minimized while still enabling reliable packet delivery determination.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If the transmitter retransmits packets without feedback information, then device complexity is reduced, but productivity decreases due to unnecessary retransmissions

Engineering Contradiction:
Improvesystem complexityVSAvoidtransmission efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The feedback mechanism provides the transmitter with information about which packets have been successfully received and decoded by receivers. This enables the transmitter to identify and retransmit only the specific packets that were not successfully received, avoiding unnecessary retransmissions of already received packets and improving transmission efficiency.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of retransmitting all packets or using complex selective retransmission protocols, the system uses a simplified feedback approach where receivers indicate successful packet reception. The transmitter then performs partial retransmission of only the necessary packets, achieving efficient resource utilization without requiring excessive complexity in the retransmission control mechanism.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4183077B1Feedback design for network coding termination in broadcasting
Publication Date: 2025.04.09 QUALCOMM INC
  • EP4183077B1 patent drawingFigure 1
  • EP4183077B1 patent drawingFigure 2
  • EP4183077B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A network node may identify a set of packets for broadcasting to a set of user equipment (UEs) and may transmit a set of encoded packets based on the set of packets. The network node may receive feedback from one or more of the UEs, and the feedback may indicate a number of successfully received packets of the set of encoded packets at each of the one or more UEs. Based on the feedback, the network node may transmit a second set of encoded packets to the set of UEs if the number of successfully received packets for at least one UE fails to satisfy a decodability threshold. The transmitter may continue to transmit sets of encoded packets until the feedback indicates that each UE has received a number of packets that satisfies the decodability threshold.