Inter-Cell Mobility Reconfiguration via L1/L2 Signaling
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Solution Overview
Problem
Existing wireless communication systems, particularly in NR and LTE, face challenges in efficiently managing inter-cell mobility and beam management, leading to increased latency and inefficiencies in handover procedures due to reliance on higher layer signaling like RRC.
Innovation Solution
Implementing L1/L2 signaling for cell reconfiguration and mobility management, allowing dynamic activation and deactivation of cells and beams, utilizing PHY layer or MAC layer signaling for faster handovers and beam adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RRC (higher layer) signaling is used for cell reconfiguration and mobility management, then the system maintains reliability and proper protocol handling, but the handover latency increases and mobility efficiency deteriorates
Solution Approach 1:
The patent segments the mobility management function into two parts: RRC layer for configuration and activation/deactivation commands, and MAC layer for fast execution of cell activation/deactivation. This segmentation allows critical time-sensitive operations to be handled by the faster MAC layer while maintaining RRC control for overall mobility management, thus reducing handover latency without sacrificing protocol reliability
Solution Approach 2:
The patent introduces MAC Control Elements (MAC-CE) as an intermediary mechanism between RRC and the physical layer. MAC-CE carries activation/deactivation commands that enable fast cell reconfiguration without requiring full RRC reconfiguration, acting as a mediator that translates high-level RRC decisions into rapid MAC-layer actions, thereby reducing handover latency while maintaining reliability
2Ease of operation
If RRC signaling is used for cell reconfiguration, then comprehensive control is maintained, but the reconfiguration speed and mobility efficiency decrease
Solution Approach 1:
The patent implements dynamic cell activation and deactivation through MAC-CE signaling, allowing the system to rapidly adapt cell configurations based on mobility conditions. Instead of static RRC-configured cells, the system dynamically activates or deactivates cells based on UE location and signal conditions, enabling fast mobility responses while maintaining comprehensive control through RRC-managed MAC-CE configurations
Solution Approach 2:
The patent employs preliminary RRC configuration of multiple candidate cells and their associated MAC-CE resources before handover is needed. When mobility requires cell reconfiguration, the UE can immediately activate pre-configured cells using pre-allocated MAC-CE resources, eliminating the need for time-consuming RRC reconfiguration during actual handover, thus improving reconfiguration speed while maintaining control
Data Source
AI summary
Aspects of the present disclosure provide a technique for wireless communications by a user equipment (UE). The UE receives signaling configuring multiple candidate target physical cell identifiers (PCIs) of at least one candidate target cell that support physical (PHY) layer or medium access control (MAC) layer mobility signaling. The UE participates in a handover procedure to a target cell associated with a selected one or more of the candidate target PCIs based on the PHY layer or the MAC layer mobility signaling. The UE modifies a configuration for at least one cell group (CG), wherein the one or more of the candidate target PCIs are associated with component carriers (CCs) of the at least one CG.