SAS Controller Spectrum Allocation via Census Tract Segmentation
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Solution Overview
Problem
Wireless networks face challenges in supporting a large number of mobile devices with high data rate demands due to limited available spectrum, leading to insufficient communication capacity.
Innovation Solution
Implementing a Spectrum Access System (SAS) controller that manages shared spectrum through fractional frequency reuse (FFR) techniques, prioritizing primary usage by incumbent devices while allocating channels to eNBs for secondary usage in census tracts, ensuring efficient communication in 3GPP networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If shared spectrum is allocated to support more mobile devices, then communication capacity increases, but interference between primary and secondary users worsens
Solution Approach 1:
The system segments the shared spectrum into multiple channels and divides census tracts into interior and exterior portions. Different channels are allocated to different geographic portions, allowing simultaneous communication without interference. The SAS controller implements this by sending configuration messages that allocate specific channels to eNBs for specific census tract portions, enabling spatial and spectral segmentation that increases capacity while preventing interference.
Solution Approach 2:
The system applies different channel allocations to different geographic locations within census tracts. Interior portions of census tracts receive different channel allocations compared to exterior portions, optimizing spectrum usage locally while maintaining overall system capacity. This local differentiation allows the system to support more users without causing interference, as each location uses appropriately assigned frequency resources.
2Productivity
If fractional frequency reuse is implemented to reduce interference, then spectrum efficiency improves, but system complexity increases
Solution Approach 1:
The SAS controller acts as an intermediary that centralizes the complexity of FFR implementation. Rather than requiring individual eNBs to implement complex FFR logic, the SAS controller receives census tract information, determines optimal channel allocations for interior and exterior portions, and sends configuration messages to eNBs. This intermediary approach maintains high spectrum efficiency through FFR while reducing the complexity burden on network elements.
Solution Approach 2:
The system changes the parameter of channel allocation based on geographic location parameters (interior vs. exterior census tract portions). By dynamically adjusting which channels are assigned to which geographic areas, the system achieves improved spectrum efficiency through FFR. The SAS controller modifies allocation parameters in response to census tract data, enabling efficient spectrum reuse without requiring complex real-time adjustments at the eNB level.
Data Source
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AI summary
Spectrum Access System, SAS, controller and base station for allocation of shared spectrum. The SAS controller receives (505) an indicator that a group of channels in the shared spectrum are available for secondary usage. The SAS controller allocates (810) one or more channels in the group to base stations for usage in one or more census tracts. The census tracts may include interior and exterior portions, in some cases. Fractional frequency reuse, FFR, techniques may be used in accordance with the interior and exterior portions of the census tracts for allocation of the channels. Channels may be allocated for Priority Access License, PAL, usage and/or General Authorized Access , GAA, usage, in some cases.