Inactive-State Uplink Feedback Mapping for Small Data Transmission

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Solution Overview

Problem

Future wireless communications networks face challenges in efficiently handling diverse devices with varying data traffic profiles and requirements, particularly in configuring uplink feedback resources for small data transmissions in the RRC_INACTIVE state, which can lead to collisions and inefficiencies.

Innovation Solution

Configuring dedicated uplink feedback resources, such as PRACH + PUCCH, PRACH + PUSCH, or PRACH alone, for UEs in the RRC_INACTIVE state to transmit HARQ-ACK and CSI feedback, using pre-defined mappings between PRACH preambles and PUCCH/PUSCH resources within a BWP, ensuring synchronization and minimizing collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If shared uplink resources are used for feedback transmission, then resource utilization is improved, but collision probability increases

Engineering Contradiction:
Improveresource utilizationVSAvoidcollision probability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments uplink feedback resources by introducing multiple feedback resource sets (first feedback resource set and second feedback resource set) with different associations to downlink data. UEs select specific resource sets based on their data characteristics, thereby dividing the shared resource pool into dedicated subsets that reduce collision probability while maintaining overall resource utilization efficiency.

Inventive Principle:
Principle #1Segmentation

2Reliability

If dedicated uplink feedback resources are configured, then collision probability is reduced, but resource overhead increases

Engineering Contradiction:
Improvecollision probabilityVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent configures multiple feedback resource sets that can serve different UE types and data scenarios. Each resource set is designed to handle specific feedback requirements, allowing the system to achieve dedicated resource allocation benefits while maintaining resource flexibility and reducing overall overhead through multi-functional resource design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies local quality by configuring different feedback resource characteristics for different UE scenarios. First feedback resource sets are optimized for certain UE types with specific time-frequency resource patterns, while second feedback resource sets serve other scenarios, ensuring each local resource allocation is optimally suited to its specific purpose rather than using uniform resources everywhere.

Inventive Principle:
Principle #3Local quality

3Productivity

If feedback resources are configured for inactive state UEs, then feedback efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvefeedback efficiencyVSAvoidresource configuration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent performs preliminary configuration of feedback resources before UEs enter the inactive state. The network configures multiple feedback resource sets in advance, and UEs store these configurations for later use. This preliminary action eliminates the need for complex real-time resource negotiation when UEs are inactive, thereby improving feedback efficiency while keeping device complexity manageable through pre-computed configurations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4668660A1Methods, communications devices, and infrastructure equipment
Publication Date: 2025.12.24 SONY GROUP CORP
  • EP4668660A1 patent drawingFigure 1
  • EP4668660A1 patent drawingFigure 2
  • EP4668660A1 patent drawingFigure 3

AI summary

A method of operating a communications device configured to transmit signals to and/or to receive signals from a wireless communications network via a wireless radio interface provided by the wireless communications network is provided. The method comprises, while the communications device is operating in an inactive state, receiving, from the wireless communications network, a small data transmission, SDT, within a set of downlink resources of the wireless radio interface, determining, based on a configuration indicated by signalling information received from the wireless communications network previously to the SDT, a set of uplink resources of the wireless radio interface, and transmitting, to the wireless communications network in the determined set of uplink resources, a feedback signal in response to the received SDT.