RAN Slice Overload Control Using PRB Thresholds and UAC Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3GPP standards do not specify how to detect slice-specific congestion in Radio Access Networks (RAN) or how to autonomously initiate Unified Access Control (UAC) to mitigate such congestion, nor do they provide mapping of slices to access categories in RAN.
Innovation Solution
Implement methods and systems to detect slice-specific overload in RAN by monitoring Physical Resource Block (PRB) utilization thresholds and identify network slices via Network Slice Selection Assistance Information (S-NSSAI), mapping slices to access categories, and initiate access class barring through the 3GPP UAC framework to mitigate congestion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If slice-specific overload control is implemented in RAN, then network congestion mitigation is improved, but system complexity increases
Solution Approach 1:
The patent introduces a mapping mechanism that acts as an intermediary between network slices and access categories. The AMF or Near-RT RIC performs the mapping of slices to operator-specific access categories, and this mapping information is sent to the gNB-CU-CP. This intermediary mapping layer enables slice-specific overload control without requiring complex modifications to the existing UAC framework, thus improving congestion mitigation while limiting system complexity growth.
Solution Approach 2:
The patent leverages the existing Unified Access Control (UAC) framework designed for general access control and adapts it for slice-specific overload control. By mapping slices to access categories, the existing UAC mechanisms can be reused for slice-specific congestion mitigation. This multi-functional approach allows the system to use established protocols and procedures for a new purpose, improving reliability without proportionally increasing complexity.
2Measurement precision
If slice mapping to access categories is implemented, then access control precision is improved, but signaling overhead increases
Solution Approach 1:
The mapping of network slices to access categories is performed in advance by the AMF or Near-RT RIC before overload conditions occur. The mapping information is prepared and sent to the gNB-CU-CP beforehand, so that when slice-specific overload detection occurs, the RAN can immediately apply the appropriate access categories without needing to perform real-time mapping calculations. This preliminary action reduces signaling overhead during critical overload situations while maintaining precise access control.
3Measurement precision
If PRB utilization monitoring is performed for slice-specific overload detection, then overload detection accuracy is improved, but processing load increases
Solution Approach 1:
The patent implements slice-specific overload control by monitoring PRB utilization, but the implementation can be selective. The system monitors Physical Resource Block (PRB) utilization for specific slices that are identified via S-NSSAI and that have been mapped to access categories. This partial monitoring approach focuses processing resources on only those slices that require slice-specific control, improving detection accuracy for critical slices while limiting the overall processing load increase by not requiring universal monitoring of all slices.
Data Source
AI summary
A method of performing slice specific overload control in a wireless communication system, including detecting a slice specific overload in a Radio Area Network (RAN) based on a Physical Resource Block (PRB) utilization threshold and a predetermined period of time, wherein a particular RAN network slice is identified via Network Slice Selection Assistance Information (S-NSSAI); mapping slices to access categories in the RAN; and informing the RAN of actions to take to mitigate the detected slice specific overload.