Reliable Groupcasting Through Proxy Feedback in Wireless Networks

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Solution Overview

Problem

Groupcasting in wireless communication networks, particularly in dense urban areas and high mobility scenarios, is unreliable due to blockages and interruptions in wireless connections, leading to challenges in timely and resource-efficient delivery of messages to all group members.

Innovation Solution

Implementing a mechanism where groupcast members who have successfully received a message act as proxies, monitoring feedback for other members and providing derived feedback to the source transmitter, allowing them to adjust retransmission strategies and ensure reliable delivery to all recipients, including those temporarily out of coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If groupcast messages are transmitted to multiple receivers in dense urban areas with blockages and interruptions, then coverage and accessibility are improved, but reliability of message delivery deteriorates

Engineering Contradiction:
Improvecoverage areaVSAvoidmessage delivery reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent applies preliminary action by having the source transmitter send a groupcast message to multiple receivers before any feedback is received. The message is transmitted in advance to all intended receivers, and the system then waits for feedback indications from each receiver about whether they successfully decoded the message. This allows the system to proactively cover all receivers in the area before dealing with delivery confirmation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where each receiver sends a feedback indication to the source transmitter about whether it successfully decoded the groupcast message. This feedback loop enables the source transmitter to identify which receivers did not receive the message correctly and needs to send retransmissions only to those specific receivers, thereby improving overall message delivery reliability in challenging urban environments.

Inventive Principle:
Principle #23Feedback

2Reliability

If retransmissions are sent to all receivers to ensure reliable delivery, then message delivery reliability is improved, but resource efficiency deteriorates

Engineering Contradiction:
Improvemessage delivery reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different receivers based on their individual feedback indications. Instead of uniformly retransmitting to all receivers, the system identifies which specific receivers failed to decode the message and sends retransmissions only to those local targets. This localized approach ensures reliable delivery to affected receivers while avoiding unnecessary energy consumption from redundant transmissions to receivers that already successfully received the message.

Inventive Principle:
Principle #3Local quality

3Reliability

If feedback is transmitted by all receivers for every retransmission, then message delivery reliability is improved, but device complexity and processing overhead worsen

Engineering Contradiction:
Improvemessage delivery reliabilityVSAvoidfeedback processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the feedback requirement from being a universal obligation for all receivers and instead conditions it on actual message reception status. Receivers that successfully decoded the groupcast message do not need to send feedback indications, while only those that failed to decode the message are required to provide feedback. This extraction of the feedback requirement from the general case reduces overall feedback processing complexity while maintaining the reliability needed to identify and serve affected receivers.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4331156B1Reliable groupcasting in wireless communication networks
Publication Date: 2025.09.03 NOKIA TECHNOLOGIES OY
  • EP4331156B1 patent drawingFigure 1
  • EP4331156B1 patent drawingFigure 2
  • EP4331156B1 patent drawingFigure 3

AI summary

According to an example aspect of the present invention, there is provided an apparatus comprising means for receiving, by a first wireless terminal, a first retransmission of a groupcast message successfully from a second wireless terminal, means for skipping, by the first wireless terminal, a transmission of feedback related to reception of the first retransmission at the first wireless terminal, means for monitoring, by the first wireless terminal, feedback from a third wireless terminal, wherein said feedback is related to reception of the first retransmission at the third wireless terminal and means for transmitting, by the first wireless terminal, derived feedback related to reception of the first retransmission at the third wireless terminal to the second wireless terminal.