5G Random Access Beam Selection Threshold Adjustment

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Solution Overview

Problem

In 5G communication systems, the random access procedure in NR (New Radio) can be delayed or fail due to improper beam selection, leading to inefficiencies in data transmission and connection establishment.

Innovation Solution

A method for performing a random access procedure in NR, where a UE selects a beam with a quality meeting a preset threshold value, adjusts the threshold value if the procedure fails, and reselects a new beam with an adjusted threshold value for retransmission, using RSRP or RSRQ values, to ensure successful contention resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a preset threshold value is used for beam selection, then beam selection is simple and fast, but random access may fail due to improper beam selection

Engineering Contradiction:

Improverandom access speedVSAvoidrandom access success rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic threshold adjustment by monitoring random access success/failure and adapting the RSRP threshold accordingly. When random access fails, the threshold is adjusted to select beams with different quality characteristics, transforming a static selection criterion into a dynamic adaptive process that resolves the contradiction between speed and success rate

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms where the outcome of random access attempts (success or failure) is fed back to adjust the beam selection threshold. This closed-loop control allows the system to learn from past performance and optimize future beam selections, ensuring both rapid access and high success rates through continuous adaptation

Inventive Principle:

Principle #23Feedback

2Loss of time

If beam selection is optimized for speed, then random access is quick, but connection reliability may deteriorate

Engineering Contradiction:

Improverandom access delayVSAvoidcontention resolution success

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The patent performs preliminary beam quality assessment using RSRP measurements before initiating random access. By pre-evaluating beam qualities against (dynamically adjusted) thresholds, the system prepares optimal beam candidates in advance, reducing actual access delay while ensuring reliable beam selection for contention resolution

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system changes the RSRP threshold parameter based on random access outcomes to balance speed and reliability. By adjusting this critical parameter dynamically, the patent enables the beam selection criterion to adapt between aggressive (fast) and conservative (reliable) modes, resolving the contradiction between access speed and contention resolution success

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11690105B2Random access performing method, and device supporting same

Publication Date: 2023.06.27 LG ELECTRONICS INC

AI summary

Provided is a method for performing a random access procedure by a terminal in a wireless communication system. The method comprises the steps of: selecting a first beam having a quality equal to or higher than a preconfigured threshold value; transmitting a random access preamble to a base station via the first beam; adjusting the threshold value when it is determined that the random access procedure has failed; and reselecting a second beam having a quality equal to or higher than the adjusted threshold value.