Dual Connectivity Control for Large and Small Cell Combinations
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Solution Overview
Problem
The dual connectivity scheme in mobile communication systems complicates communication control if not properly managed, particularly when user terminals establish connections with multiple cells managed by different base stations.
Innovation Solution
Implementing a dual connectivity scheme that allows user terminals to connect with a combination of large and small cells, where the small cell is within the coverage of the large cell and operates on a different frequency, with coordinated resource assignment by schedulers at each base station to manage communication effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dual connectivity scheme is unconditionally permitted for all cell combinations, then user terminals can establish connections with multiple cells managed by different base stations to improve throughput, but communication control complexity increases significantly
Solution Approach 1:
The patent applies local quality by differentiating between two types of cell combinations: intra-eNB cell pairs and inter-eNB cell pairs. For intra-eNB combinations, dual connectivity is permitted with standard control procedures. For inter-eNB combinations, the patent imposes additional constraints requiring the second cell to be a small cell within the coverage of the first cell, and modifies handover control to prevent unnecessary handovers. This localized differentiation allows dual connectivity to improve throughput where appropriate while avoiding the complexity explosion that would occur with unconditional permission for all cell combinations.
2Productivity
If dual connectivity is permitted with multiple cell combinations, then resource allocation from multiple cells can be achieved, but handover control becomes difficult and radio link failures increase
Solution Approach 1:
The patent applies preliminary action by pre-establishing the coverage relationship between large cells and small cells before dual connectivity is activated. The base station determines in advance which small cells fall within the coverage of which large cells, and this coverage information is stored and used to control subsequent handover decisions. When a user terminal is connected to a large cell and a small cell simultaneously, the base station can predict whether handover of the small cell will cause radio link failure by checking the coverage relationship, thereby preventing harmful handovers before they occur and maintaining radio link stability while allowing efficient resource allocation from multiple cells.
Data Source
AI summary
A mobile communication system supports a dual connectivity scheme. The dual connectivity scheme is a scheme in which a user terminal establishes a pair of connections with a pair of cells including a combination of cells managed by different base stations. The user terminal is permitted to apply the dual connectivity scheme only when the pair of cells is a combination of a large cell and a small cell provided within a coverage of the large cell.