UE-Triggered Cell Switching Using Low-Layer Mobility Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing handovers between cells or cell groups, particularly in scenarios requiring faster mobility transitions due to the limitations of layer 3 (L3) triggered handovers, which can lead to increased latency and inefficiencies.
Innovation Solution
Implementing layer 1 (L1) or layer 2 (L2) triggered mobility (LTM) mechanisms, where user equipment (UE) initiates handovers based on configuration information from a base station, allowing for faster and more dynamic cell switching through L1/L2 signaling, including beam management and timing advance management, and enabling conditional handovers with LTM conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If layer 3 (L3) triggered handovers are used, then handover control is centralized and reliable, but mobility latency increases and efficiency decreases
Solution Approach 1:
The patent segments the handover control function into two parts: L3 layer maintains configuration and decision authority (reliability), while L1/L2 layers execute rapid switching operations (low latency). This segmentation allows the system to benefit from both centralized control and fast execution by distributing functions across different protocol layers.
Solution Approach 2:
The patent implements preliminary action by pre-configuring handover parameters, target cell information, and switching conditions at L3 layer before mobility events occur. When L1/L2 triggered handover is activated, the pre-prepared configuration enables immediate execution without waiting for L3 processing, thus reducing mobility latency while maintaining L3 oversight.
2Productivity
If layer 1 (L1) or layer 2 (L2) triggered mobility is implemented, then handover speed increases and efficiency improves, but system complexity increases
Solution Approach 1:
The patent makes lower layers (L1/L2) multi-functional by enabling them to perform both traditional functions (signal transmission, error control) and handover execution functions. This universality allows L1/L2 to handle handover operations without requiring entirely new dedicated structures, thereby improving handover efficiency while limiting the increase in system complexity.
Solution Approach 2:
The patent introduces L3 configuration information as an intermediary that bridges the gap between centralized control requirements and distributed execution needs. The L3 layer provides configuration messages that mediate between the control plane and the fast-executing L1/L2 layers, enabling efficient handover execution while maintaining system manageability through a standardized interface.
3Measurement precision
If conditional handovers with LTM conditions are used, then mobility accuracy improves, but signaling overhead increases
Solution Approach 1:
The patent applies partial action by implementing conditional handovers only when specific LTM conditions are met, rather than requiring continuous full handover signaling. The system monitors multiple conditions (signal quality thresholds, cell reselection criteria, timing conditions) and triggers handover only when necessary, thereby improving mobility decision accuracy while reducing overall signaling overhead compared to unconditional frequent handovers.
Data Source
AI summary
An example first network entity for wireless communication includes a communication interface; and one or more processors coupled to the communication interface, wherein the one or more processors are configured to: send, via the communication interface, configuration information to a second network entity, the configuration information specifying a condition to switch from a current cell to a target cell; exchange, via the communication interface, first information of a communication session with the second network entity on the current cell; receive, from the second network entity via the communication interface, switch information representing that the condition has been met; and exchange, via the communication interface, second information with the second network entity on the target cell via the communication session.