Cell Grouping and Power Headroom Reporting in Dual Connectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In heterogeneous wireless networks, the existing technologies face challenges in efficiently controlling multiple cells due to identifier conflicts and lack of real-time state awareness between base station devices, leading to suboptimal packet scheduling and power headroom reporting.
Innovation Solution
A terminal device and base station device system that groups cells into primary and secondary cell groups, with individual power headroom reporting and cell index management using RRC messages, enabling efficient control and scheduling of multiple cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If distributed packet scheduling is performed between base station devices, then real-time control responsiveness is improved, but device complexity increases due to coordination requirements between multiple base stations
Solution Approach 1:
The patent segments the network control into two distinct parts: centralized control for cell index allocation (managed by one base station) and distributed control for packet scheduling (performed by multiple base stations). This segmentation allows each base station to independently perform packet scheduling using locally allocated cell indexes, achieving real-time responsiveness without the coordination overhead that would result from fully distributed control.
2Device complexity
If cell indexes are allocated independently by each base station, then device complexity is reduced, but identifier conflicts occur between different base stations
Solution Approach 1:
The patent implements preliminary action by having one base station allocate cell indexes to other base stations before distributed packet scheduling begins. This pre-allocation ensures that each base station receives unique cell indexes in advance, preventing identifier conflicts during subsequent distributed scheduling operations while keeping the allocation process simple and centralized.
3Measurement precision
If power headroom reporting is performed for all cells, then measurement precision is improved, but loss of time increases due to processing overhead
Solution Approach 1:
The patent extracts and reports only the power headroom information for the primary secondary cell separately and prominently in the power headroom report. By focusing on this specific cell that is most critical for dual connectivity operations, the system achieves precise measurement where needed most while reducing overall reporting overhead and processing time compared to reporting all cells equally.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In a terminal device that uses a plurality of cells, the plurality of cells are grouped into a cell group for a first base station device and a cell group for a second base station device, and processing for activation/deactivation of the plurality of cells is performed on a cell in the cell group that receive a control element indicating the activation/deactivation, and in a case where the cell group for the second base station is added, a power headroom indicating capacity available for transmit power in the plurality of cells is determined as being triggered, and power headrooms of the plurality of cells that are activated are reported.