Radio Network Node Primary Cell Re-Selection Without Random Access
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Solution Overview
Problem
The existing primary cell re-selection process in wireless communication networks is time-consuming and prone to connection loss due to unnecessary random access procedures, especially when user equipment synchronizes with secondary cells, leading to delays and resource inefficiencies.
Innovation Solution
A method where the radio network node transmits an RRCConnectionReconfiguration signal indicating that the user equipment does not need to perform a random access procedure when changing the primary cell to a secondary cell, allowing for direct uplink allocation and synchronization, thus skipping the unnecessary random access step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the user equipment performs a random access procedure when changing primary cell from first cell to second cell, then connection reliability is improved, but re-selection delay increases and resource efficiency deteriorates
Solution Approach 1:
The user equipment performs synchronization with the second cell before the primary cell re-selection is completed. The synchronization is prepared in advance during the handover process, so when the re-selection occurs, the random access procedure can be skipped or shortened, reducing delay while maintaining connection reliability
Solution Approach 2:
The random access procedure is extracted or removed from the mandatory steps of primary cell re-selection when the user equipment is already synchronized with the target cell. This eliminates unnecessary delays and resource consumption while maintaining connection reliability through alternative verification mechanisms
2Reliability
If the user equipment performs a random access procedure during primary cell re-selection, then cell synchronization is ensured, but resource efficiency deteriorates and connection failures may occur
Solution Approach 1:
Synchronization with the target cell is performed in advance during the handover preparation phase. The user equipment aligns its timing and frequency with the second cell before the actual primary cell re-selection, ensuring synchronization is already established when re-selection occurs, thus eliminating the need for resource-intensive random access procedures
Solution Approach 2:
When the user equipment is already synchronized with the second cell, the random access procedure is skipped entirely during primary cell re-selection. The system rushes through the re-selection by directly confirming the cell change without the traditional random access step, improving resource efficiency while maintaining synchronization through pre-established alignment
Data Source
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AI summary
A radio network node(RNN) (202) and a method therein, for handling of changing primary cell from a first cell (204) to a second cell (206) during re-selection of primary cell of a user equipment (UE) (208). The RNN is configured to serve the first cell, the UE is located within the first cell and is served by the RNN, and RNN and the UE are comprised in a communications system (200). The RNN transmits an RRCConnectionReconfiguration signal to the UE, which signal comprises an indication that the UE does not need to perform a random access procedure for the second cell when changing primary cell from the first cell to the second cell.