Msg3 Repetition RV Determination via RAR Indication
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Solution Overview
Problem
In 5G NR systems, the determination of the redundancy version (RV) used for repetition of Msg3 in the random access procedure is not clearly defined, leading to unclear RV usage during Msg3 repetition.
Innovation Solution
A method where a terminal device receives a Random Access Response (RAR) carrying an uplink grant for Msg3 repetition, determines the RV based on the RAR, and performs the repetition using the determined RV, with the RAR optionally including an RV indication field to specify the RV for each repetition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repetition of Msg3 is adopted to improve coverage performance, then transmission reliability is improved, but the determination of RV for repetition is unclear
Solution Approach 1:
The patent introduces an intermediary element (RV indication field or specific field in RAR message) that carries RV information from the network device to the terminal device. This intermediary resolves the contradiction by providing a clear mechanism for RV determination while maintaining the repetition function for improved reliability.
Solution Approach 2:
The patent changes the parameter transmission mechanism by explicitly including RV indication information in the RAR message. This parameter change resolves the ambiguity in RV determination while preserving the repetition-based reliability improvement.
2Area of stationary object
If RAR is used to schedule repetition of Msg3, then coverage performance is improved, but RV selection for repetition is not clearly defined
Solution Approach 1:
The patent uses the RAR message as an intermediary carrier that includes both the scheduling information for Msg3 repetition and the RV indication field. This resolves the contradiction by embedding the RV selection instructions within the existing RAR framework, maintaining coverage improvement while clarifying RV selection.
Solution Approach 2:
The patent makes the RAR message multi-functional by having it serve both as a scheduling message for Msg3 repetition and as a carrier for RV indication information. This universal approach resolves the contradiction without requiring separate signaling mechanisms.
3Reliability
If repetition of PUSCH carrying Msg3 is adopted, then transmission reliability is improved, but the method for determining RV is not clearly defined
Solution Approach 1:
The patent introduces an RV indication field as an intermediary element within the RAR message structure. This simple intermediary provides clear RV determination instructions, resolving the contradiction by adding minimal complexity while ensuring reliable repetition transmission.
Solution Approach 2:
The patent enables the terminal device to self-determine the RV by providing it with the necessary indication information in the RAR message. This self-service approach resolves the contradiction by allowing the terminal to autonomously select the correct RV without complex external coordination.
Data Source
AI summary
Provided are a transmission method, a terminal device and a network device. The method includes that the terminal device receives a Random Access Response (RAR), and the RAR carries an Uplink grant (UL grant) for repetition of a Message 3 (Msg3) in a random access procedure. The terminal device determines an RV used for the repetition of the Msg3. Based on the RAR, the terminal device performs repetition of the Msg3 by use of the RV. In the embodiments of the disclosure, the RV used for Msg3 repetition which is scheduled by the RAR may be determined.