RACH-Less Handover PUSCH Mapping for Downlink Beam Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In new radio (NR) RACH-less handover processes, the lack of random access channel (RACH) transmission and reference signal selection leads to reduced reliability due to the directional nature of downlink signals, making it difficult to determine the manner of transmitting downlink signals.

Innovation Solution

Establishing an association relationship between the resource of the physical uplink shared channel (PUSCH) and a reference signal in the target cell, such as SSB or CSI-RS, to facilitate reliable RACH-less communication by determining the appropriate reference signal beam for subsequent downlink transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If RACH transmission and reference signal selection are removed in handover process, then handover speed and efficiency are improved, but communication reliability deteriorates due to inability to determine downlink signal transmission manner

Engineering Contradiction:
Improvehandover speedVSAvoidcommunication reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-establishing the association relationship between PUSCH resources and reference signals before handover occurs. The terminal device determines this association in advance during the handover preparation phase, so that when RACH-less handover is executed, the downlink signal transmission manner is already determined, eliminating the reliability issue while maintaining fast handover speed.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If association relationship between PUSCH resource and reference signal is established, then downlink signal transmission manner can be determined and communication reliability is improved, but system complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling the terminal device to autonomously determine the association relationship between PUSCH resources and reference signals without requiring complex network-side coordination or additional signaling procedures. The terminal uses its own capabilities to establish this relationship, thereby improving reliability while avoiding increased system complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4712559A1Transmission method, terminal, network side device and medium
Publication Date: 2026.03.18 VIVO MOBILE COMM CO LTD
  • EP4712559A1 patent drawingFigure 1~2
  • EP4712559A1 patent drawingFigure 3~5
  • EP4712559A1 patent drawingFigure 6

AI summary

This application discloses a transmission method, a terminal, a network-side device, and a medium, and belongs to the communication field. The transmission method in embodiments of this application includes: transmitting, by a terminal, a first physical uplink shared channel PUSCH to a target cell in a random access channel-less RACH-less handover process, where there is an association relationship between a resource of the first PUSCH and a first reference signal of the target cell.