Cell-Specific Reselection Priorities for Pico Cell Load Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cell reselection methods in wireless communications networks lack the ability to prioritize cells on the same frequency differently, leading to inefficient utilization of pico cells and potential overload on macro cells, especially in scenarios with mixed macro and micro/pico cell deployments.
Innovation Solution
Introducing cell-specific reselection priority values that allow for prioritization of cells on the same frequency, enabling the radio base station to transmit distinct priority values for each cell, thereby increasing the granularity of cell reselection priorities from frequency level to cell level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cell reselection priority is provided only at frequency level, then the system is simple to operate, but pico cells cannot be prioritized over macro cells on the same frequency leading to inefficient capacity utilization
Solution Approach 1:
The patent segments the cell reselection priority mechanism by introducing cell-specific priority values (qOffsetCell) that can be individually configured for each neighboring cell. This allows the system to differentiate between macro cells and pico cells on the same frequency, enabling pico cells to be prioritized for UE reselection while maintaining separate control for each cell type.
Solution Approach 2:
The patent applies local quality by allowing different offset values to be assigned to different cells based on their specific characteristics. Pico cells can be assigned negative offsets to attract UEs, while macro cells can be assigned positive offsets to discourage reselection, creating locally optimized reselection behavior for each cell type within the same frequency.
2Productivity
If all cells on the same frequency have equal priority, then the configuration is simple, but macro cells become overloaded as UEs cannot be offloaded to pico cells
Solution Approach 1:
The patent changes the reselection parameter by introducing cell-specific offset values (qOffsetCell) that modify the effective priority of individual cells. By setting negative offsets for pico cells and positive offsets for macro cells, the system dynamically adjusts reselection behavior to balance load across different cell types while maintaining manageable configuration through standardized offset ranges.
3Productivity
If cell-specific priority values are introduced, then pico cells can be effectively prioritized, but the system complexity increases
Solution Approach 1:
The patent segments the priority configuration by introducing cell-specific qOffsetCell parameters that can be independently set for each neighboring cell. This segmentation allows operators to selectively apply negative offsets to pico cells to attract UEs while maintaining positive offsets for macro cells, achieving fine-grained control without overwhelming system complexity.
Solution Approach 2:
The patent applies local quality by allowing different offset values to be assigned to different cells based on their specific characteristics. Pico cells can be assigned negative offsets to attract UEs, while macro cells can be assigned positive offsets to discourage reselection, creating locally optimized reselection behavior for each cell type within the same frequency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The application relates to cell reselection in idle mode as standardised by TS 36.304, and in particular to priority-based cell reselection, which improves the performance of cell reselection in the presence of multiple RATs which may coexist in the same geographical location. Current cell re-selection between frequencies is based on absolute priorities, where each frequency has an associated priority. In several network scenarios, however, it is beneficial, and even essential, to prioritize cells on the same frequency differently. Embodiments herein thus introduce a cell specific reselection priority in that the reselection priority values comprise priority values for the different cells. Embodiments herein increase the granularity of the cell reselection priorities from frequency level to cell level, i.e. to be per cell rather than just per frequency when it is desired. Preceding the actions proposed by the application, it is assumed that a UE is associated with a first cell (Cell 1) of a radio base station, which first cell has a first frequency f1 and a wireless communications network comprises a second cell (Cell 2) having a second frequency f2, which second cell has at least partly overlapping coverage with the first cell, and a third cell (Cell 3) having the second frequency, which third cell has at least partly overlapping coverage with the first cell. Then the radio base station transmits cell reselection priority values to the UE, wherein the cell reselection priority values comprise a first priority value for the second cell, and a second priority value for the third cell. In the prior art, the UE within coverage of Cell 3 would stay camped on Cell 1 (b1), whereas, with the proposed priority values, the UE in idle mode, will when camped on Cell 1, autonomously perform inter-frequency measurements and detect when it enters the coverage of Cell 3 and autonomously perform cell reselection to Cell 3 when Cell 3 becomes good enough (a1).