CU-DU Paging Mechanism for 5G RRC Inactive Context Management
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Solution Overview
Problem
The current paging mechanism in 5G communication systems with a CU-DU architecture experiences faults, leading to system errors when UE is in an RRC inactive status, and the admission control mechanism is weak, causing failures during UE network access.
Innovation Solution
The CU provides indication information to the DU to differentiate between core network-based and RAN-based paging, allowing the DU to determine the paging type and notify the UE accordingly, and the CU explicitly instructs the DU to release or retain the UE context based on accurate status determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current paging mechanism is used in CU-DU architecture, then the system can operate with basic paging functionality, but system errors occur when UE is in RRC inactive status
Solution Approach 1:
The paging mechanism is segmented into two distinct types: core network-based paging and RAN-based paging. This segmentation allows the system to handle different paging scenarios through dedicated procedures, eliminating the confusion that causes system errors in RRC inactive status. The CU-DU architecture leverages this segmentation by implementing specific indication fields for each paging type.
Solution Approach 2:
An indication field acts as an intermediary between the CU and DU to convey paging type information. This intermediary mechanism enables the DU to correctly interpret paging requests without requiring complex autonomous decision-making, thereby improving reliability while maintaining manageable complexity.
2Reliability
If the current admission control mechanism is used, then the network access process is simple, but system errors occur due to weak admission control
Solution Approach 1:
The admission control mechanism performs preliminary actions by sending indication information to the DU before the actual access procedure. This preliminary indication allows the DU to prepare appropriate resources and configurations, preventing system errors that would occur with weak or reactive admission control.
Solution Approach 2:
The admission control mechanism incorporates feedback through indication fields that convey access status and requirements from the CU to the DU. This feedback loop enables the DU to adjust its behavior based on network conditions and UE status, improving reliability without requiring overly complex autonomous control at the DU level.
3Measurement precision
If the CU does not provide explicit paging type indication, then the signaling overhead is reduced, but the DU cannot accurately determine paging type for proper UE notification
Solution Approach 1:
The paging type indication is extracted as a separate, dedicated field within the existing signaling structure. This extraction allows the DU to accurately determine paging type without significantly increasing overall signaling overhead, as the indication is integrated into existing message formats rather than requiring separate transmissions.
Solution Approach 2:
The system utilizes parameter changes within existing indication fields to convey paging type information. By modifying the interpretation or values of existing parameters based on UE status (connected or inactive), the system transmits additional information without requiring entirely new signaling elements, thus minimizing overhead while maintaining precision.
Data Source
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AI summary
Embodiments of this application provide a communication method, so as to help resolve a prior-art problem that a paging mechanism existing in a radio access network in a centralized unit CU-distributed unit DU architecture exists faultiness and may result in a paging failure. The method includes the following processes: sending, by a centralized unit, a paging message to a distributed unit, where the paging message carries indication information indicates that the paging is paging originated from a core network or the paging is paging originated from a radio access network; and determining, by the distributed unit according to the indication information, that the paging is paging originated from the core network or the paging is paging originated from the radio access network. According to the method, the paging mechanism in the Background is improved, reducing system paging failures.