Adaptive HARQ Retransmission for Video Packet Priority

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Despite increased bandwidth capacity in wireless communication networks, efficiently and reliably transporting video data remains challenging due to intensive network resource usage and latency requirements in applications like video conferencing and cloud gaming.

Innovation Solution

Implementing adaptive Hybrid Automatic Repeat Request (HARQ) retransmission strategies based on video packet priority, using cross-layer control and logical channel control to optimize HARQ parameters, allowing for different maximum retransmissions for various logical channels and prioritizing video packets accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HARQ retransmissions are increased to improve reliability, then packet loss is reduced, but latency increases

Engineering Contradiction:
Improvepacket delivery reliabilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic adjustment of maximum HARQ retransmission values based on logical channel priority and video packet importance. Instead of using a fixed retransmission limit, the system adapts the maximum retransmissions parameter (maxHARQ-Tx) dynamically, allowing higher retransmission counts for high-priority video packets and lower counts for less critical data, thereby optimizing the trade-off between reliability and latency on a per-packet basis

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the HARQ parameter (maximum retransmission value) based on the priority level of the logical channel and the importance of the video packet. By modifying the maxHARQ-Tx parameter dynamically according to packet priority, the system achieves higher reliability for critical video data without uniformly increasing latency for all transmissions

Inventive Principle:
Principle #35Parameter changes

2Productivity

If HARQ parameters are adjusted frequently to optimize video quality, then video transmission performance improves, but system complexity increases

Engineering Contradiction:
Improvevideo transmission efficiencyVSAvoidHARQ control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments video traffic into multiple logical channels with different priority levels (e.g., high priority for I-frames and P-frames, low priority for B-frames or less critical data). Each logical channel is assigned specific HARQ parameters including maximum retransmission values. This segmentation allows differentiated HARQ control without requiring complex per-packet analysis, simplifying the overall system while maintaining optimized video transmission

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system pre-configures HARQ parameters for each logical channel before video transmission begins. The maximum retransmission values and other HARQ characteristics are determined in advance based on the priority classification of each logical channel, eliminating the need for real-time parameter adjustments during transmission and reducing control complexity

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2813020B1Method and apparatus for video aware hybrid automatic repeat request
Publication Date: 2019.06.19 VID SCALE INC
  • EP2813020B1 patent drawingFigure 1A~1C
  • EP2813020B1 patent drawingFigure 2
  • EP2813020B1 patent drawingFigure 3

AI summary

HARQ parameters (e.g., maximum HARQ retransmission values) may be adapted. Cross-layer control and/or logical channel control may be used to select a maximum number of HARQ retransmissions, for example based on packet priority and/or QCI values. Respective priorities of video packets may be used to select one of a plurality of logical channels associated with a video application that may be established at a source wireless hop and/or a destination wireless hop. The logical channels have different HARQ characteristics. Different maximum HARQ retransmission values may be determined for select logical channels, for example such that packets of different priorities may be transmitted over different logical channels. One or more of the channels may be associated with one or more transmission queues that may have different priority designations. Video packets may be reordered (e.g., with respect to transmission order) within the transmission queues, for example in accordance with respective HARQ parameters.