Terminal Device HARQ Process Management for Asynchronous Uplink

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

There is a lack of a concrete method for introducing asynchronous HARQ in the uplink, including methods for switching between synchronous and asynchronous HARQ, identifying HARQ processes related to uplink grants, and processing HARQ buffers.

Innovation Solution

The implementation of a terminal device and a base station device that utilize a communication method enabling efficient switching between synchronous and asynchronous HARQ in the uplink, along with methods for identifying HARQ processes and processing HARQ buffers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If synchronous HARQ is used in the uplink, then the system maintains simplicity and compatibility with existing LTE standards, but the system lacks flexibility in handling varying traffic conditions and cannot optimize communication efficiency for different scenarios

Engineering Contradiction:
ImproveHARQ mode flexibilityVSAvoidHARQ management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic HARQ mode switching that allows the system to transition between synchronous and asynchronous HARQ modes based on traffic conditions and service requirements. The base station can configure different HARQ modes for different uplink grants, enabling flexible adaptation to varying communication scenarios while maintaining manageable complexity through standardized switching mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the HARQ system by introducing configurable HARQ process identifiers and buffer management parameters. Through RRC signaling and DCI formats, the system can adjust HARQ-related parameters dynamically, allowing transition between synchronous and asynchronous modes without fundamental system redesign.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If asynchronous HARQ is introduced in the uplink, then the system gains flexibility to handle diverse traffic conditions and optimize communication efficiency, but the system lacks concrete methods for switching between HARQ modes and managing HARQ processes

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidHARQ process management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the HARQ management into distinct components: HARQ entity, HARQ process, and HARQ buffer. Each uplink grant can be associated with a specific HARQ process identifier, allowing independent management of multiple HARQ processes. This segmentation enables flexible asynchronous HARQ operation while keeping individual process management straightforward.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces HARQ process identifiers as intermediaries between the uplink grant and the HARQ buffer. These identifiers act as mediators that link scheduling decisions to specific HARQ processes and buffers, enabling efficient asynchronous HARQ management without requiring complex direct mapping between grants and buffers.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a HARQ process identifier is included in the uplink grant, then the system can accurately identify and manage specific HARQ processes, but the control signaling overhead increases

Engineering Contradiction:
ImproveHARQ process identification accuracyVSAvoidcontrol signaling bits
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by including HARQ process identifiers selectively in DCI formats based on the specific scheduling scenario. The HARQ process identifier is included only when necessary for asynchronous HARQ operation or when multiple HARQ processes need to be distinguished, rather than being universally present in all uplink grants, thus optimizing signaling overhead.

Inventive Principle:
Principle #3Local quality

4Productivity

If multiple HARQ processes are managed simultaneously, then the system can handle multiple outstanding transmissions and improve resource utilization, but the buffer management complexity increases

Engineering Contradiction:
Improveresource utilizationVSAvoidbuffer management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the HARQ buffer into multiple independent buffer regions, each associated with a specific HARQ process identifier. This segmentation allows each buffer region to be managed independently, simplifying the overall buffer management complexity while enabling simultaneous handling of multiple HARQ processes and improving resource utilization.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3288307B1Terminal device, base station device, integrated circuit, and communication method
Publication Date: 2025.06.04 SHARP KK
  • EP3288307B1 patent drawingFigure 1
  • EP3288307B1 patent drawingFigure 2
  • EP3288307B1 patent drawingFigure 3

AI summary

Provided is a terminal device that receives RRC layer information indicating an asynchronous HARQ for a secondary cell, and a first random access response, which is a random access response including fields for indicating an uplink grant and a Temporary C-RNTI and is related to a non-contention based random access procedure on the secondary cell, that manages multiple HARQ processes, and that delivers the uplink grant to an HARQ process that instructs the transmission unit to transmit the MAC layer data in accordance with the uplink grant. In a case that the RRC layer information indicating the asynchronous HARQ is configured, a HARQ process in which the uplink grant included in the first random access response is delivered is determined based on the value of a field for indicating the Temporary C-RNTI included in the first random access response.