Multicast PDU Feedback Mechanism for Wireless Reliability

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Solution Overview

Problem

Current multicast transmission in wireless communication is unreliable due to its operation in unacknowledged mode, leading to issues such as packet loss and reduced service reliability, especially in scenarios requiring high reliability like industrial applications or software updates.

Innovation Solution

A communication method where receiving apparatuses feed back their status on received data PDUs to the sender, allowing the sender to determine if retransmission is necessary, thereby improving the reliability of multicast services by using timers and sequence numbers to manage data PDU reporting and retransmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multicast transmission operates in unacknowledged mode, then transmission speed and system complexity are maintained, but reliability deteriorates due to packet loss

Engineering Contradiction:
ImprovereliabilityVSAvoidcomplexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where receiving terminals send status information about received data PDUs back to the transmitting base station. This allows the base station to identify which packets were successfully received and which need retransmission, thereby improving reliability while maintaining controlled complexity through targeted feedback rather than continuous acknowledgment

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses timers to trigger status reporting at predetermined intervals or conditions. Instead of waiting for errors to occur or implementing complex real-time monitoring, the system proactively reports status based on timer expiration or specific triggering events, improving reliability through systematic monitoring without requiring complex continuous detection mechanisms

Inventive Principle:
Principle #10Preliminary action

2Reliability

If status reporting is triggered by multiple conditions in parallel, then reliability is improved through comprehensive monitoring, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoidcomplexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic triggering where multiple conditions (timer expiration, receiving status indications, sequence number gaps) can trigger status reporting. The system adapts to different scenarios by responding to whichever condition is met first, providing comprehensive monitoring for improved reliability while avoiding the need for a single complex centralized control mechanism

Inventive Principle:
Principle #15Dynamics

3Reliability

If the first timer expires, then periodic status reporting ensures reliability, but time consumption increases

Engineering Contradiction:
ImprovereliabilityVSAvoidtime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses periodic timer-based status reporting to ensure reliable transmission. The timer triggers status updates at regular intervals or after specific time durations, ensuring that the base station receives information about packet reception status systematically. This periodic mechanism improves reliability by ensuring timely detection of packet loss without requiring continuous monitoring, thus managing time consumption efficiently

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3993455B1Communication method, apparatus and system
Publication Date: 2024.08.07 HUAWEI TECH CO LTD
  • EP3993455B1 patent drawingFigure 1~2
  • EP3993455B1 patent drawingFigure 3A~3B
  • EP3993455B1 patent drawingFigure 4

AI summary

This application relates to the field of communication technologies, and discloses a communication method, apparatus, and system, to resolve a problem that existing multicast transmission is unreliable. The method includes: A first apparatus determines a first status protocol data unit PDU, where the first status PDU is used to indicate a receiving status of at least one data PDU from a second apparatus, and the at least one data PDU is transmitted in a multicast mode. The first apparatus sends the first status PDU to the second apparatus. The first apparatus feeds back the receiving status of the data PDU to the second apparatus, to notify the second apparatus of a data PDU that is not received, so that the second apparatus may determine, based on a service requirement, whether the data PDU needs to be retransmitted. Therefore, reliability of multicast transmission is improved.