Two-Step Random Access BWP Overlap for Flexible Preamble Groups
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Solution Overview
Problem
The existing 2-step random access procedures in NR wireless communication networks face challenges in efficiently configuring preamble group B resources due to conflicting criteria for PUSCH resource sizing, limiting flexibility and efficiency in uplink transmissions.
Innovation Solution
Configuring the active BWP to overlap with 2-step RA resources on the initial BWP, allowing connected UEs to use MsgA PRACH and MsgA PUSCH resources in the initial BWP without switching active BWPs, and enabling multiple preamble group B configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the UE is restricted to using 2-step RA resources only on the active BWP, then the active BWP can be kept simple and manageable, but the flexibility and adaptability of preamble group B configuration is limited
Solution Approach 1:
The initial BWP is designed to serve multiple functions: it provides 2-step RA resources for idle/inactive mode UEs and also serves as a resource pool for connected mode UEs in the active BWP. This multi-functionality allows the system to maintain flexibility in preamble group B configuration while avoiding the need for separate dedicated resources, thereby resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The patent introduces a new dimension of resource sharing by allowing connected mode UEs to access 2-step RA resources from the initial BWP (which was previously only for idle/inactive UEs). This cross-BWP resource utilization creates an additional layer of flexibility in preamble group B configuration without requiring separate dedicated resources, thus improving adaptability without proportionally increasing complexity.
2Adaptability or versatility
If multiple preamble group B configurations are implemented, then the adaptability for different uplink transmission scenarios is improved, but the device complexity and configuration overhead increase
Solution Approach 1:
The initial BWP's 2-step RA resources are designed to be universally accessible to both idle/inactive mode UEs and connected mode UEs. This universal resource pool can accommodate multiple preamble group B configurations with different PUSCH resource sizes, allowing the system to handle various uplink transmission scenarios (small data, large data, different pathloss conditions) without requiring separate dedicated configurations for each scenario, thus managing complexity while maintaining adaptability.
3Ease of operation
If the active BWP does not overlap with initial BWP resources, then the active BWP can be optimized for its specific purposes, but BWP switching becomes necessary and adds to the procedure complexity
Solution Approach 1:
The patent merges the resource spaces of the initial BWP and active BWP by configuring the active BWP to overlap with the initial BWP's 2-step RA resources. This merging allows connected mode UEs to use the same resource pool without requiring BWP switching, thereby simplifying the random access procedure and reducing operational complexity while maintaining the optimization benefits of having a dedicated active BWP for other purposes.
Data Source
AI summary
Techniques are provided to enable use of more than two preamble group Bs during random access (RA) for connected UEs. This flexibility is achieved by configuring the active BWP to overlap with the 2-step RA resources on the initial BWP, configuring different sizes of preamble group B in the initial BWP and the active BWP, a allowing connected UEs in the active BWP to use the MsgA PRACH and MsgA PUSCH resources in the initial BWP without switching active BWP.