Random Access Message Parameter Selection for Flexible NR RACH

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Solution Overview

Problem

Existing 2-step random access channel (RACH) processes in new radio (NR) lack flexibility in transmission parameter configuration, leading to resource waste and deteriorated transmission performance for terminal devices due to uniform application of parameters across all devices in a cell.

Innovation Solution

Terminal devices select a target transmission parameter from a plurality of options, including redundancy version (RV) and number of repetitions, based on factors like user capability, path loss, transmit power, transport block size, and content priority, to optimize random access message transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a uniform transmission parameter is configured for all terminal devices in a cell, then the configuration is simple and easy to implement, but transmission flexibility is poor and resource waste occurs

Engineering Contradiction:
Improvetransmission flexibilityVSAvoidparameter configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the uniform transmission parameter into multiple parameter sets, where each parameter set corresponds to different transmission conditions (e.g., different numbers of repetitions, different redundancy versions). Terminal devices are associated with different parameter sets based on their characteristics, enabling differentiated transmission strategies without requiring complete system redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allowing different terminal devices to use different transmission parameters tailored to their specific conditions (path loss, capability, traffic type). Instead of a one-size-fits-all approach, each device receives parameters optimized for its local transmission environment, improving flexibility while maintaining manageable configuration through localized parameter selection.

Inventive Principle:
Principle #3Local quality

2Reliability

If an excessively large number of repetitions is configured, then transmission reliability is improved, but resource waste increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidresource waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the parameter of number of repetitions dynamically based on terminal device conditions. Devices with poor channel conditions receive larger repetition counts to ensure reliability, while devices with good channel conditions use smaller repetition counts to avoid resource waste. This parameter adaptation resolves the contradiction between reliability and resource consumption.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If an excessively small number of repetitions is configured, then resource waste is reduced, but transmission performance deteriorates

Engineering Contradiction:
Improveresource efficiencyVSAvoidtransmission performance
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent dynamically adjusts the repetition parameter based on actual transmission conditions. Devices experiencing poor channel conditions automatically receive increased repetition counts to maintain performance, while devices with good conditions benefit from reduced repetitions for efficiency. This conditional parameter change resolves the contradiction between resource efficiency and transmission performance.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If improper redundancy version is used, then transmission efficiency is improved, but transmission performance deteriorates

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidtransmission performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs different redundancy versions (RV) based on terminal device characteristics and transmission conditions. The RV parameter is adapted to match the specific needs of each device, optimizing the balance between transmission efficiency and performance. This parameter adaptation allows the system to achieve both efficiency and reliability simultaneously.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3998829B1Random access message transmission method and device
Publication Date: 2026.04.01 VIVO MOBILE COMM CO LTD
  • EP3998829B1 patent drawingFigure 1~2
  • EP3998829B1 patent drawingFigure 3~4
  • EP3998829B1 patent drawingFigure 5~6

AI summary

Embodiments of the present disclosure disclose a random access message transmission method and a device. The method is performed by a terminal device, and includes: selecting a target transmission parameter from a plurality of transmission parameters, where the target transmission parameter includes at least one of an RV, an RV sequence, and a number of repetitions; and sending a random access message according to the target transmission parameter.