Random Access Response LBT Signaling for Faster Msg3 Access

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in channel access mechanisms, particularly in listen-before-talk (LBT) mode for random access response (RAR), which affect the efficiency of channel access type indication and cyclic prefix extension, especially in evolving networks like 5G.

Innovation Solution

Implementing methods and apparatuses for listen-before-talk (LBT) mode in wireless communication systems that allow for determining channel access type and cyclic prefix extension based on UE-specific LBT modes, independent of RAR indications, and enabling RAR to include channel access type fields irrespective of LBT performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LBT procedure is performed before RAR transmission, then channel access reliability is improved, but transmission delay increases

Engineering Contradiction:

Improvechannel access reliabilityVSAvoidtransmission delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The base station performs LBT procedure in advance before RAR transmission and indicates the channel access type in the RAR message. This allows the UE to determine whether LBT is needed for Msg3 transmission beforehand, avoiding unnecessary LBT procedures and reducing transmission delay while ensuring reliable channel access when needed.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If channel access type indication is always included in RAR, then access efficiency is improved, but message overhead increases

Engineering Contradiction:

Improveaccess efficiencyVSAvoidmessage overhead

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The channel access type field in RAR serves multiple functions: it indicates whether LBT is required for Msg3, provides channel access guidance for different uplink transmission scenarios, and enables efficient resource utilization. This multi-functional approach improves access efficiency without proportionally increasing overhead.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If UE determines LBT requirement based on RAR indication, then channel access accuracy is improved, but processing complexity increases

Engineering Contradiction:

Improvechannel access accuracyVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses parameter changes in the channel access type field (different values indicating different LBT requirements) to convey precise channel access instructions. The UE processes these parameter changes to determine LBT requirements accurately. This approach balances precision with manageable processing complexity by using standardized parameter interpretations.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12574966B2Method and apparatus for listen-before-talk mode for random access response in a wireless communication system

Publication Date: 2026.03.10 ASUSTEK COMPUTER INC

AI summary

Methods, systems, and apparatuses are provided for listen-before-talk (LBT) mode for random access response (RAR) in a wireless communication system so that RAR indication of channel access type and cyclic prefix (CP) extension can be more efficient. A method of a User Equipment (UE) can comprise initiating a random access procedure, receiving a RAR, wherein the RAR comprises a channel access type indication, and determining whether to perform LBT for a Msg3 based on the channel access type indication in RAR.