UE Cell Reselection After RRC Failure on Problem Cells
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Solution Overview
Problem
User Equipment (UE) experiences call drops and silent calls due to cyclic attempts to establish an RRC connection with a problem cell, which has the strongest signal strength but causes Radio Link Failure (RLF), leading to prolonged call silence and eventual call termination.
Innovation Solution
The UE lowers the carrier frequency priority of the problem cell upon timer expiration and performs accelerated cell reselection to a different cell, reducing the duration of camping on the problem cell and optimizing call continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE always chooses to camp on the cell with the strongest signal strength and highest priority during cell reselection, then the cell selection process is simple and fast, but the UE cannot successfully establish RRC connection due to the problem cell causing cyclic failures and call drops
Solution Approach 1:
The patent changes the priority parameter of the cell based on RRC connection establishment results. When RRC connection establishment fails, the priority of the current cell is reduced, causing the UE to select alternative cells in subsequent reselections. This dynamic parameter adjustment resolves the contradiction by maintaining simple selection criteria while improving connection success rate through adaptive priority modification.
Solution Approach 2:
The patent implements a feedback mechanism where the UE monitors RRC connection establishment outcomes and uses this information to adjust cell priority. The failed connection attempt triggers a priority reduction, which feeds back into the cell selection process. This closed-loop feedback resolves the contradiction by using connection success information to dynamically optimize cell selection without increasing overall system complexity.
2Productivity
If the UE continuously attempts to establish RRC connection with the problem cell after entering idle state, then the cell reselection process is straightforward, but the call remains silent for a long time and may be dropped
Solution Approach 1:
The patent modifies the priority parameter dynamically based on connection outcomes. When the UE fails to establish RRC connection with a cell, it reduces that cell's priority, which accelerates the cell reselection process in subsequent idle state transitions. This parameter change reduces silent call duration by preventing repeated attempts on problematic cells while maintaining straightforward reselection procedures.
Solution Approach 2:
The patent performs preliminary priority reduction when RRC connection establishment fails, before the UE returns to idle state. This preliminary action prevents the UE from immediately reselecting the same problematic cell, thereby reducing silent call duration. The priority adjustment is made in advance, so when the UE next enters idle state, it automatically selects a different cell without prolonged delays.
Data Source
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AI summary
Embodiments of this application provide a communication method and a related device. According to the communication method, once a UE cannot establish, in a call, an RRC connection with a network device corresponding to a cell currently being camped on, the UE may lower a priority of the cell that the UE is currently camped on, so that the UE may choose another cell other than a problem cell to camp on through cell reselection subsequently, thereby avoiding problems of call drops and silent calls caused by camping on the problem cell for a long time.