Dynamic Link Selection for Wireless Retransmission

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Solution Overview

Problem

In wireless communications, especially in Wi-Fi and WLAN based on IEEE 802.11 standards, unreliable links due to weak signal strength or interference lead to increased retransmissions, which are inefficient and delay-prone, particularly in latency-sensitive applications like IoT and AI, where deterministic scheduling is required for low-latency traffic.

Innovation Solution

Implementing dynamic link selection methods for multi-link devices (MLDs) to establish Block Ack agreements or protected Block Ack agreements, allowing for the selection of more reliable links for retransmissions, thereby improving transmission reliability by recommending alternative links for retransmissions based on real-time status and SINR information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retransmissions are performed on the same link to improve transmission reliability, then transmission success ratio increases, but delay increases and reliability does not improve for latency-sensitive applications

Engineering Contradiction:
Improvetransmission reliabilityVSAvoiddelay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic link selection where the transmitting station switches from static retransmission on the original link to dynamic selection of alternative links based on real-time channel conditions. The system monitors link quality metrics and dynamically determines the optimal link for retransmission, making the retransmission process adaptive rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of link selection from fixed (same link) to variable (alternative links). By monitoring channel conditions and selecting different links based on current state, the system transforms the retransmission process from a static parameter to a dynamic one that adapts to changing environmental conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple retransmissions are performed on a given link to improve transmission success ratio, then reliability improves, but delay bound requirements cannot be met for latency-sensitive applications

Engineering Contradiction:
Improvetransmission success ratioVSAvoiddelay bound
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically selects retransmission links based on real-time channel conditions rather than persisting on the original link. This dynamic approach allows the system to meet delay bounds by quickly identifying viable alternative links when the original link proves unreliable.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the retransmission process across multiple available links rather than concentrating all retransmission attempts on a single link. By dividing the retransmission workload across different links, the system can parallelize retransmission attempts and reduce overall delay.

Inventive Principle:
Principle #1Segmentation

3Reliability

If interference persists on the link, then retransmission reliability decreases, but lowering MCS rate of retransmission increases delay

Engineering Contradiction:
Improveretransmission reliabilityVSAvoiddelay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the retransmission process from the interfered link and relocates it to alternative links with better channel conditions. By separating the retransmission function from the problematic link, the system avoids the interference issue without needing to lower the MCS rate.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces alternative links as intermediary channels for retransmission. These intermediary links serve as mediators between the transmitting and receiving stations, providing a cleaner transmission path that avoids the interference present on the original link.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Loss of time

If deterministic scheduling is implemented for low-latency traffic, then delay bound requirements are met, but transmission reliability must be improved within the scheduled time interval

Engineering Contradiction:
Improvedelay boundVSAvoidtransmission reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent performs preliminary link quality assessment and proactively selects optimal links for potential retransmissions before the scheduled transmission time. By preparing alternative links in advance and monitoring their quality, the system ensures that reliable retransmission paths are ready when needed within the deterministic scheduling framework.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4307590A1Dynamic link selection for reliable retransmission in wireless communications
Publication Date: 2024.01.17 MEDIATEK INC
  • EP4307590A1 patent drawingFigure 1
  • EP4307590A1 patent drawingFigure 2
  • EP4307590A1 patent drawingFigure 3

AI summary

Techniques pertaining to dynamic link selection for reliable retransmission in wireless communications are described. A multi-link device, MLD, establishes a block acknowledgement, Block Ack, agreement or a protected Block Ack agreement with one other MLD on one or more enabled links for dynamic link selection (1410). The MLD communicates with the other MLD on at least one of the one or more enabled links prior to termination of the Block Ack agreement or the protected Block Ack agreement (1420).