User Equipment Dynamic Random Access Procedure Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In NR-based wireless communication systems, the 2-step random access procedure is inefficient due to the need for the user equipment to transmit a payload along with a preamble, which can fail due to poor radio quality, necessitating a switch to the 4-step procedure.

Innovation Solution

The user equipment dynamically switches between the 2-step and 4-step random access procedures based on the radio quality and communication status, with triggers including failure detection and explicit or implicit instructions from the base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the 2-step random access procedure is used, then the random access completion time is reduced, but the transmission reliability deteriorates due to payload transmission requirements

Engineering Contradiction:
Improverandom access completion timeVSAvoidtransmission reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent implements dynamic switching between 2-step and 4-step random access procedures based on real-time radio quality conditions. The terminal determines whether to use the 2-step or 4-step procedure by evaluating radio quality metrics, allowing the system to adaptively optimize between speed and reliability depending on current channel conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the random access procedure by switching between two different procedural modes (2-step and 4-step) based on radio quality thresholds. This parameter change allows the system to select the appropriate procedure type that matches current communication conditions, resolving the contradiction between speed and reliability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the 2-step random access procedure is used, then the procedure efficiency is improved, but the communication reliability deteriorates under poor radio quality conditions

Engineering Contradiction:
Improveprocedure efficiencyVSAvoidcommunication reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the random access procedure type based on real-time radio quality assessment. When radio quality is good, the 2-step procedure is used for high efficiency; when radio quality deteriorates, the system switches to the 4-step procedure to maintain reliability, thus dynamically optimizing both efficiency and reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates feedback mechanisms where the terminal continuously monitors radio quality conditions and uses this feedback to determine the appropriate random access procedure. The system receives radio quality information, compares it against thresholds, and adjusts the procedure selection accordingly, creating a closed-loop control that balances efficiency and reliability.

Inventive Principle:
Principle #23Feedback

3Speed

If the terminal must transmit payload along with preamble in 2-step procedure, then the random access speed is improved, but the transmission failure rate increases under poor radio quality

Engineering Contradiction:
Improverandom access speedVSAvoidtransmission success rate
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent implements dynamic procedure selection where the terminal switches between 2-step and 4-step random access based on radio quality. When radio quality is sufficient, the faster 2-step procedure is used; when radio quality is poor, the more robust 4-step procedure is selected, dynamically optimizing the balance between speed and success rate.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary anti-action by assessing radio quality conditions before initiating the random access procedure. By evaluating the channel conditions in advance, the system prevents transmission failures by selecting the appropriate procedure type that can succeed under current conditions, rather than attempting the faster but riskier 2-step procedure when conditions are poor.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3920637B1Terminal, system and communication method
Publication Date: 2025.06.18 NTT DOCOMO INC
  • EP3920637B1 patent drawingFigure 1
  • EP3920637B1 patent drawingFigure 2
  • EP3920637B1 patent drawingFigure 3

AI summary

A user equipment includes a transmitting unit configured to transmit signals required for a first random access procedure and a second random access procedure, a receiving unit configured to receive signals required for the first random access procedure and the second random access procedure, and a control unit configured to switch the first random access procedure and the second random access procedure according to a predetermined switch trigger, wherein the first random access procedure and the second random access procedure are different in a number of steps required to complete a random access procedure.