Internet of Vehicles HARQ Feedback Timing Without Central Scheduling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing V2X communication technologies, particularly in LTE, do not support multicast or unicast communication at the physical layer, necessitating a modification to enable higher communication rates, shorter delays, and more reliable communication quality required by 5G NR V2X services.

Innovation Solution

Implementing HARQ feedback mechanisms in V2X devices without a central node by allowing each device to autonomously determine a feedback time window based on the end time of user data transmission, using predefined or dynamically configured time window offsets, and selecting suitable time-frequency resources for HARQ feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If broadcast information is used for V2X communication, then device complexity is reduced, but communication reliability and efficiency deteriorate due to lack of targeted feedback mechanisms

Engineering Contradiction:
Improvecommunication system complexityVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the feedback mechanism by introducing separate feedback time windows for different user data transmissions. Each user data transmission has its own dedicated feedback window, allowing targeted HARQ feedback without requiring a centralized scheduling node, thus improving reliability while maintaining distributed system simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements HARQ feedback mechanisms where receiving devices send acknowledgment feedback to transmitting devices within specific feedback time windows. This feedback loop enables reliable unicast and multicast communication by allowing retransmissions based on feedback, directly improving communication reliability

Inventive Principle:
Principle #23Feedback

2Productivity

If autonomous feedback time window determination is implemented, then communication efficiency improves, but resource collision risk increases without central coordination

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidresource allocation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-configuring feedback time window offsets before communication occurs. These offsets are determined in advance based on user data transmission timing, allowing devices to autonomously calculate their feedback windows without real-time central coordination, thus maintaining efficiency while preventing resource collisions

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic feedback time window allocation where each user data transmission has its own configurable feedback window offset. This dynamic approach allows the system to adapt feedback timing to specific transmission requirements while maintaining autonomous operation without central scheduling, balancing efficiency and collision avoidance

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4221021B1Method, apparatus, and system for transmitting feedback information between internet of vehicles devices
Publication Date: 2025.10.29 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4221021B1 patent drawingFigure 1~2
  • EP4221021B1 patent drawingFigure 3~5
  • EP4221021B1 patent drawingFigure 6~7

AI summary

The present invention relates to the technical field of wireless communications. Disclosed is a method for transmitting feedback information between Internet of Vehicles devices. The method comprises: a first Internet of Vehicles device sends first user data to a second Internet of Vehicles device; the first Internet of Vehicles device and the second Internet of Vehicles device respectively determine a feedback time window of the first user data according to a transmission end time of the first user data; the second Internet of Vehicles device sends hybrid automatic repeat request (HARQ) feedback information of the first user data to the first Internet of Vehicles device in the feedback time window of the first user data; the first Internet of Vehicles device receives the HARQ feedback information in the feedback time window of the first user data. The solution determines a sending time window of feedback information by means of a transmission end time of user data, without providing a central node to schedule a feedback resource, thereby implementing the support of HARQ feedback during Internet of Vehicles communications.