User Apparatus Carrier Selection for Random Access Procedure
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Solution Overview
Problem
In an NR wireless communication system, when a user apparatus does not support SUL while a serving cell supports SUL, the user apparatus performs a redundant determination operation regarding the use of SUL, leading to inefficiencies in the random access procedure.
Innovation Solution
A user apparatus is equipped with a transmission unit, a reception unit, and a control unit that determines the carrier to be used for the random access procedure. The control unit checks if a first carrier (such as SUL) is configured and supported in the serving cell, and if so, uses that carrier for the random access procedure, with operations performed in the MAC or RRC layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the user apparatus performs redundant determination operation for SUL carrier selection, then the carrier selection can be exhaustive, but the random access procedure efficiency deteriorates
Solution Approach 1:
The patent extracts and removes the redundant SUL carrier determination operation from the random access procedure. When the user apparatus determines that SUL is not supported or not configured, it exits the SUL determination process early and proceeds directly to NUL carrier selection, eliminating unnecessary processing steps while maintaining accurate carrier selection.
Solution Approach 2:
The patent performs preliminary checks to determine SUL support and configuration status before initiating the full carrier selection process. By checking SUL availability in advance (through capability indication and configuration verification), the system prepares the carrier selection path beforehand, avoiding redundant operations during the actual random access procedure.
2Measurement precision
If the user apparatus checks SUL support and configuration status, then the carrier selection becomes accurate, but the operation complexity increases
Solution Approach 1:
The patent implements a tiered determination approach where the user apparatus performs only the necessary subset of checks based on initial conditions. If SUL is clearly not supported or not configured, only minimal checks are performed. The full determination sequence is executed only when needed, reducing average operation complexity while maintaining detection accuracy when SUL is available.
Data Source
AI summary
A user apparatus includes a transmission unit for transmitting a signal related to a random access procedure in a serving cell; a reception unit for receiving a signal related to the random access procedure in the serving cell; and a control unit for determining a carrier to be used for the random access procedure, the carrier being configured to the serving cell. The control unit determines whether a first carrier is configured to the serving cell, determines whether the first carrier of the serving cell is supported when the first carrier is configured to the serving cell, and determines to use the first carrier for the random access procedure when the first carrier of the serving cell is supported. An operation of determining the carrier to be used for the random access procedure is performed in at least one of a MAC layer and an RRC layer.