Data Retransmission Timer for URLLC Latency Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In ultra-reliable and low-latency communications (URLLC) scenarios, existing data retransmission methods often result in expiration data and redundant transmission due to inadequate consideration of varying latency requirements and system configurations, leading to inefficiencies and resource wastage.

Innovation Solution

A data retransmission method that employs a timer to determine whether to send retransmission data, starting the timer when new data is obtained and stopping transmission if the remaining time is insufficient for data transmission, ensuring that data is not sent beyond the maximum transmission latency, thereby avoiding redundant transmission and conserving resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transmit end performs retransmission based on maximum retransmission quantity without considering latency, then retransmission reliability is improved, but transmission latency increases and expiration data is caused

Engineering Contradiction:
Improveretransmission reliabilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The transmit end starts a timer before sending data (when obtaining new to-be-sent data), establishing a latency constraint in advance. This preliminary action ensures that subsequent retransmission decisions are made with awareness of the latency budget, preventing expiration data from being transmitted.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic timer-based latency management that adapts retransmission behavior to remaining time constraints. The timer value dynamically decreases, and retransmission decisions are adjusted based on whether sufficient time remains, making the system flexible rather than fixed.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the transmit end continues retransmission until maximum retransmission quantity is reached, then data delivery reliability is improved, but redundant transmission occurs and resources are wasted

Engineering Contradiction:
Improvedata delivery reliabilityVSAvoidtransmission resources
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The timer is started in advance with a value representing the maximum allowable latency. This preliminary setup creates a natural stopping condition for retransmission, preventing redundant transmissions that would occur if only maximum retransmission quantity were used without time consideration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The timer provides continuous feedback about remaining latency budget. Before each retransmission, the transmit end checks whether the timer has sufficient remaining time, creating a feedback loop that prevents wasteful retransmissions when the latency budget is exhausted.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3550754B1Data retransmission method and communication device
Publication Date: 2023.07.05 HUAWEI TECH CO LTD
  • EP3550754B1 patent drawingFigure 1
  • EP3550754B1 patent drawingFigure 2~3
  • EP3550754B1 patent drawingFigure 4

AI summary

Embodiments of this application provide a data retransmission method and a communications apparatus. The method includes: starting, by a transmit end, a timer before transmitting new data to a receive end, where a preset value of the timer is a maximum transmission latency corresponding to a service type of the data; retransmitting, by the transmit end, the data to the receive end when data needs to be retransmitted; transmitting, by the transmit end, the data to the receive end; and stopping sending, by the transmit end, retransmission data to the receive end when the timer expires, where the retransmission data is a part or all of the data. In this way, the following prior-art problem is avoided: Because a maximum retransmission quantity is not exhausted but a maximum transmission latency is exhausted, the transmit end still sends data, and consequently the receive end receives expiration data. This can avoid redundant transmission and save transmission resources.