CBRS Dual Cell Radio Node for Stable Coverage and Dynamic Capacity
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Solution Overview
Problem
Current small cell radio access networks face challenges in providing stable and dynamic wireless capacity, particularly in indoor environments, due to limitations in spectrum allocation and interference management within the citizens band radio spectrum (CBRS).
Innovation Solution
Implementing radio nodes with dual identities, where a primary cell identity provides a stable coverage layer using Priority Access License (PAL) channels and a secondary cell identity offers a dynamic capacity layer using Generic Authorized Access (GAA) channels, managed by a centralized services node for optimized channel allocation and interference protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single cell identity is used in small cell radio access networks, then device complexity is reduced, but the ability to provide both stable coverage and dynamic capacity is compromised
Solution Approach 1:
The cell identity is segmented into two distinct identities: a first cell identity (PCI-1) for stable coverage layer and a second cell identity (PCI-2) for dynamic capacity layer. This segmentation allows each identity to serve its specific function independently, resolving the contradiction between adaptability and complexity by dividing the single cell identity into specialized components.
Solution Approach 2:
The radio node is configured with multi-functionality by supporting both first and second cell identities simultaneously. The first identity provides stable coverage while the second identity provides dynamic capacity, allowing the same radio node to fulfill multiple roles without requiring separate physical nodes, thus improving adaptability without proportionally increasing complexity.
2Reliability
If Priority Access License (PAL) channels are used for stable coverage, then coverage reliability is improved, but spectrum utilization efficiency deteriorates due to restricted access
Solution Approach 1:
The spectrum access is segmented into two layers: PAL channels dedicated to stable coverage provision and GAA channels for dynamic capacity addition. This segmentation allows PAL channels to maintain their reliability function while GAA channels compensate for the restricted access by providing additional spectrum utilization through dynamic sharing mechanisms.
Solution Approach 2:
The system merges PAL and GAA channel operations within the same radio node, combining the reliability benefits of licensed access with the efficiency benefits of unlicensed access. The first cell identity operates on PAL channels for stable coverage while the second cell identity operates on GAA channels for dynamic capacity, achieving both reliability and productivity simultaneously.
3Productivity
If Generic Authorized Access (GAA) channels are used for dynamic capacity, then spectrum utilization efficiency is improved, but interference management complexity increases
Solution Approach 1:
Interference management is segmented by separating the functions of the first and second cell identities. The first identity on PAL channels handles stable coverage with simplified interference protection, while the second identity on GAA channels handles dynamic capacity with enhanced interference coordination. This segmentation reduces overall complexity by assigning different management strategies to different identities rather than managing all interference uniformly.
Solution Approach 2:
The second cell identity acts as an intermediary that manages interference between GAA channels and PAL channels. By configuring the second identity specifically for GAA operations, it mediates the interaction between dynamic unlicensed access and stable licensed access, coordinating resource allocation and interference avoidance between the two access types without requiring complex centralized control.
4Adaptability or versatility
If dual cell identities are configured in radio nodes, then network adaptability is improved, but signaling overhead increases
Solution Approach 1:
The dual cell identity configuration segments the network functionality into coverage layer and capacity layer, with each layer having dedicated identities and resource pools. This segmentation reduces signaling overhead by allowing independent management of each layer's resources without requiring cross-layer coordination, thus maintaining adaptability while reducing the information exchange burden between network entities.
Data Source
AI summary
A radio node having a primary cell identity and a secondary cell identity operates the two cell identities at the same time. They are localized and occupy the same geographic location, but operate at different frequencies/channels. The primary cell (PCell) may encompass, e.g., one or more channels, e.g., 20 MHz, and the same can act as a coverage layer, providing a stable spectrum for communications, as these channels do not change. The secondary cell (SCell) operates at the same time, and can operate with higher reuse using multiple GAA channels as they are available (their availability may vary as they are dynamically allocated). This layer can act as a “capacity” layer as the multiple GAA channels can allow for high throughput when needed. That is, they are dynamically allocated, but high capacity can be enabled as a high number of such channels may be available at any one time.