Macro-to-Micro Base Station Switching via SFN-SFN Lists
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Solution Overview
Problem
In UMTS communications, the large number of micro base stations exceeds the protocol-defined limit of neighbor cells, leading to decreased mobility and call drops due to the inability of traditional UE to determine a reasonable switching neighbor cell.
Innovation Solution
The method involves multiplexing scrambling codes and creating a system frame number (SFN)-system frame number (SFN) relation list between macro and micro base stations, allowing the network to correctly identify and switch to a target cell by using scrambling code information, timing advance (TM), and offset (OFF) information in measurement reports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large number of micro base stations are deployed to improve indoor coverage and relieve traffic pressure, then the coverage quality and network capacity are improved, but the number of neighbor cells exceeds the protocol-defined maximum of 31, leading to decreased mobility and call drops
Solution Approach 1:
The patent segments the identification of neighbor cells by introducing a two-stage process: first using scrambling code groups to categorize multiple micro base stations, then using SFN-SFN offset values to identify specific cells within each group. This segmentation allows the system to handle more than 31 neighbor cells by dividing them into manageable groups, resolving the contradiction between supporting many micro base stations and the protocol's neighbor cell limit.
Solution Approach 2:
The patent adds a new dimension for cell identification by introducing SFN-SFN offset values as a second identification layer beyond scrambling codes. This dimensional expansion allows the system to uniquely identify more cells than the traditional single-dimension scrambling code approach, enabling support for large numbers of micro base stations while maintaining protocol compatibility.
2Ease of operation
If traditional UE measurement control is used to identify neighbor cells, then the implementation is simple, but the UE cannot determine the appropriate target cell when the number of micro base stations exceeds 31
Solution Approach 1:
The patent introduces SFN-SFN offset values as an intermediary element that bridges the gap between the UE's measurement capabilities and the network's cell identification requirements. This intermediary allows the UE to report measurements for multiple cells using extended identification methods, enabling reliable target cell determination even when more than 31 micro base stations are present, thus resolving the contradiction between simple operation and reliable switching.
Data Source
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AI summary
A network-side device and a macro base station to micro base station switching method relate to a universal mobile telecommunications system. The method includes: multiplexing part of scrambling codes in reserved scrambling codes to micro base station cells, and configuring them to a user equipment; a network side creating a SNF-SFN relation list between various base station cells according to existing determined neighbor cell relations and cell synchronization information in a measurement report reported by the user equipment; when the user equipment reports a switching measurement report of a target cell, the network side determining a target cell in actual switching and performing the switching according to the scrambling code information in the switching measurement report, TM and OFF information in the cell synchronization information and the SFN-SFN relation list. The embodiment of the present invention further discloses a network-side device. By means of multiplexing scrambling codes and creating SFN-SFN list information between the cells, the technical solution of the present application can accurately identify a specific target cell in switching, thus realizing the mobile continuity.