PSCell Fast Re-establishment for Dual Connectivity RRC Recovery
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Solution Overview
Problem
In dual connectivity networks, the re-establishment of a radio resource control connection is complex and inefficient, particularly when a radio link failure occurs, as existing methods require cell selection and random access procedures, leading to increased outage times.
Innovation Solution
The implementation of a fast cell reconfiguration procedure, where a primary secondary cell (PSCell) takes over the functionality of the primary cell (PCell) upon request from the user equipment (UE), reducing the need for cell selection and random access by providing pre-configured UE context and security information, allowing for immediate re-establishment of the RRC connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the user equipment performs cell selection and random access procedures to re-establish the RRC connection after radio link failure, then the connection can be re-established, but the outage time is increased
Solution Approach 1:
The patent applies preliminary action by pre-configuring the PSCell with the UE context information before radio link failure occurs. The PSCell is pre-selected and prepared as a target cell for fast re-establishment, eliminating the need for cell selection procedures after failure. This pre-positioning of recovery resources directly reduces outage time while ensuring reliable connection restoration.
2Loss of time
If the PSCell is configured with pre-configured UE context and security information, then the RRC connection can be re-established faster, but the device complexity increases
Solution Approach 1:
The patent applies universality by enabling the PSCell to serve multiple functions: it acts as a secondary cell for normal dual connectivity operation and simultaneously serves as a pre-prepared target cell for fast RRC re-establishment. This multi-functionality allows the same cell to provide both data transmission services and emergency recovery services, reducing re-establishment time without requiring separate dedicated recovery infrastructure.
3Ease of operation
If the PSCell takes over the functionality of the PCell upon request, then the re-establishment procedure is simplified, but the adaptability of the network configuration is reduced
Solution Approach 1:
The patent applies dynamics by making the PSCell's functionality adaptive rather than fixed. The PSCell is configured with the capability to take over PCell functionality upon receiving a specific request from the UE, but this role transition is not mandatory or permanent. The network can dynamically adjust the PSCell's role based on current conditions, maintaining configuration flexibility while enabling simplified re-establishment when needed.
Data Source
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AI summary
A method and apparatus are provided. The method comprises: providing a primary secondary cell by a second node for a user equipment operating in dual connectivity with a first node and the second node; and receiving a request from the user equipment requesting that the primary secondary cell provide the functionality of a primary cell for the user equipment when a radio link between the user equipment and a primary cell provided by the first node is lost.