CU-DU Control Plane Split for Lower-Latency RAN Signaling
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Solution Overview
Problem
The increasing number of distributed units coupled to a centralized unit in future wireless networks leads to a heavy processing burden and increased access stratum control plane latency, particularly when the centralized unit is deployed in the core network, necessitating a more efficient distribution of control plane functionality.
Innovation Solution
The proposed solution involves splitting the radio resource control functionality between the centralized and distributed units, allowing for flexible configuration based on the deployment location of the centralized unit, with the distributed unit handling lower-layer protocols and certain control plane functions, and coordinating with the centralized unit to manage higher-layer protocols and configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the centralized unit handles all control plane functions, then control functionality is centralized and manageable, but processing burden increases and access stratum control plane latency increases
Solution Approach 1:
The patent segments the control plane functionality into two distinct components: the Control Plane Configuration Function (CPCF) handling higher-layer protocols and the Access Stratum Control Plane Function (AS-CP) handling lower-layer protocols. This segmentation distributes processing burden from the centralized unit to the distributed unit, reducing latency in access stratum operations while maintaining centralized configuration management.
2Productivity
If more distributed units are coupled to the centralized unit, then network capacity and coverage increase, but processing burden on the centralized unit increases
Solution Approach 1:
The patent extracts the Access Stratum Control Plane Function from the centralized unit and places it in the distributed unit. This extraction allows the centralized unit to focus on configuration management while distributed units independently handle access stratum control, enabling the network to scale with more distributed units without proportionally increasing centralized processing burden.
3Device complexity
If the centralized unit is deployed in the core network, then network architecture is simplified, but access stratum control plane latency increases
Solution Approach 1:
The patent applies local quality by placing the Access Stratum Control Plane Function locally at the distributed unit, closer to the radio access network edge where it is needed. This local placement reduces latency for access stratum operations while the centralized unit in the core network maintains simplified architecture for configuration management, achieving both goals simultaneously.
Data Source
AI summary
The present application relates to devices and components including apparatus, systems, and methods for control plane (CP) operations in a split centralized unit (CU)—distributed unit (DU) architecture.