Differentiated HARQ Feedback for URLLC and eMBB Services

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Solution Overview

Problem

The HARQ mechanism in LTE systems is not suitable for 5G systems, as it cannot provide differentiated retransmission services for ultra-reliable and low-latency communication services, due to its inability to handle multiple types of services with varying latency and reliability demands within the same subframe.

Innovation Solution

The proposed solution involves generating separate feedback bits for different types of services within a subframe, allowing the access network device to provide differentiated retransmission services based on the feedback, ensuring timely data transmission for ultra-reliable and low-latency communication services.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If single-bit HARQ feedback per TB is used, then the system complexity is reduced, but the ability to support differentiated retransmission services for multiple service types (eMBB and URLLC) is lost

Engineering Contradiction:
ImproveHARQ feedback complexityVSAvoidService differentiation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The feedback information is segmented into multiple bits, where each bit corresponds to a specific service type (eMBB or URLLC). This allows the system to provide differentiated feedback for different service types while maintaining manageable complexity through structured segmentation of the feedback mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The feedback mechanism transitions from a single dimension (one-bit feedback) to multiple dimensions by introducing service-type-specific feedback bits. This dimensional expansion enables the system to distinguish between different service types (eMBB and URLLC) and provide appropriate differentiated retransmission services for each.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of time

If differentiated feedback bits are generated for different service types, then the retransmission timeliness for URLLC services is improved, but the feedback information overhead increases

Engineering Contradiction:
ImproveRetransmission delayVSAvoidFeedback information overhead
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

Different feedback bits are allocated to different service types based on their specific requirements. URLLC services receive dedicated feedback bits that enable faster, prioritized retransmission, while eMBB services use separate feedback bits with different timing requirements. This local quality differentiation ensures that each service type receives appropriate treatment without unnecessarily increasing overhead for all services.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3605911B1HARQ feedback method, apparatus, and system
Publication Date: 2023.06.21 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3605911B1 patent drawingFigure 1~2
  • EP3605911B1 patent drawingFigure 3
  • EP3605911B1 patent drawingFigure 4

AI summary

HARQ feedback method, apparatus and system, relating to the field of communications. The method includes: receiving, by a first equipment, a data subframe transmitted by a second device, wherein the data sub frame comprises a first slot corresponding to a first type of service and a second slot corresponding to a second type of service; generating, by the first equipment, the HARQ feedback according to the data subframe, wherein the HARQ feedback includes a first feedback bit corresponding to the first slot and a second feedback bit corresponding to the second slot; and transmitting, by the first equipment, the HARQ feedback to the second device. In examples of the present disclosure, with respect to different types of service, the first equipment performs HARQ feedback by employing different feedback bits, such that the device provides differentiated data retransmission services for different type of services according to the feedback bits, thereby ensuring the timeliness of transmitting data for ultra reliable and low latency communication service.