RRC Cell Group Switching Using Lower-Layer Handover Signaling
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Solution Overview
Problem
In wireless communication systems, particularly in scenarios involving RRC information block applications, the expiration of timers can lead to incorrect determination of successful application, resulting in potential disconnection and increased latency during cell handovers, which is exacerbated by frequent handovers in 5G networks with smaller cells and diverse services.
Innovation Solution
The proposed solution involves using lower layer signaling, such as the physical or MAC layer, to indicate RRC information block application, allowing for pre-configured synchronization and timely stopping of timers without random access, thereby reducing latency and ensuring accurate determination of successful application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional L3 RRC signaling is used for cell handover, then the handover process is reliable and controllable, but the handover latency is large (tens to hundreds of milliseconds)
Solution Approach 1:
The patent applies preliminary action by pre-configuring target cell information including downlink reference signals and timing advance parameters before handover occurs. The UE performs downlink synchronization with the target cell in advance, so when handover is triggered, the UE can immediately start uplink transmission without waiting for random access, thereby reducing handover latency while maintaining reliability through pre-established synchronization.
Solution Approach 2:
The patent replaces the traditional mechanical random access process (L3 RRC signaling based) with a lower-layer based handover mechanism using L1/L2 signaling. By substituting the complex RRC handover procedure with physical layer synchronization and MAC layer control, the system achieves faster handover execution while the network maintains control through configured parameters and measurement results.
2Measurement precision
If timer is stopped only upon successful RRC information block application, then the timer expiration can indicate failure, but the timer cannot be stopped in time for L1L2 triggered mobility without random access
Solution Approach 1:
The patent implements feedback by having the lower layer (L1/L2) provide timely feedback information to the RRC layer about the handover status. When L1L2 triggered mobility occurs without random access, the feedback mechanism allows the timer to be stopped promptly based on the actual handover completion status, ensuring both timely timer stopping and accurate failure indication through proper feedback loops.
Solution Approach 2:
The patent applies preliminary action by pre-establishing the timer stopping conditions and feedback mechanisms before handover occurs. The RRC layer is pre-configured with the ability to stop the timer based on lower layer feedback, so when L1L2 triggered mobility happens, the timer can be stopped immediately without waiting for RRC layer confirmation, ensuring timely termination while maintaining measurement precision.
3Adaptability or versatility
If frequent cell handovers are performed in 5G networks with smaller cells, then the system can better serve diverse applications and improve resource allocation, but the service interruption and latency increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-synchronizing the UE with the target cell before handover occurs. The UE performs downlink synchronization with the target cell in advance, receives and stores target cell system information, and prepares uplink transmission parameters. This preliminary preparation eliminates the need for time-consuming random access during handover, allowing frequent handovers to occur with minimal service interruption while maintaining system adaptability to diverse 5G services.
Data Source
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AI summary
Disclosed in the present application are a method used for wireless communication, and a device. The method comprises: receiving at least one RRC information block, each RRC information block amongst the at least one RRC information block being used for configuring a cell group, and the application of any RRC information block amongst the at least one RRC information block depending on receiving a signaling other than the at least one RRC information block; receiving a second signaling, the second signaling being a signaling of a protocol layer below the RRC layer, and, in response to receiving the second signaling, applying the first RRC information block, the second signaling indicating the first RRC information block amongst the at least one RRC information block, the application of the first RRC information block not comprising random access, and the expiration of a first timer being used for determining that the first RRC information block fails to be applied. The present application may achieve better mobility management.