Cellular Network Relocation via Primary Secondary User-Plane Split
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-density microcellular networks, frequent user-plane interruptions occur due to the need for frequent replacement of Primary Cells (PCells), leading to traffic control issues and packet loss, especially when handover processes involve security reconfiguration and protocol stack resets.
Innovation Solution
A method for cellular network relocation where the source eNB sends a relocation request to the target eNB, transferring context information of the primary user-plane function, allowing seamless handover without interrupting the user-plane, by maintaining continuous execution of secondary user-plane functions and avoiding protocol stack resets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If handover is performed in high-density microcellular networks, then coverage continuity is maintained, but user-plane interruptions and packet loss occur due to frequent PCell replacement
Solution Approach 1:
The patent segments the user-plane functions into primary and secondary functions. The primary user-plane function (PUC) is transferred from source eNB to target eNB, while the secondary user-plane function (SUC) remains at the source eNB. This segmentation allows the PCell to be relocated without interrupting the user-plane data flow, as the SUC continues to handle data packets seamlessly during the handover process.
Solution Approach 2:
The source eNB acts as an intermediary during the handover process by maintaining the SUC and forwarding data packets to the target eNB. This intermediary role ensures that user-plane data transmission continues uninterrupted even as the PCell changes, effectively mediating between the old and new primary cells.
2Reliability
If security reconfiguration and protocol stack resets are performed during handover, then security is maintained, but user-plane transmission is interrupted
Solution Approach 1:
The patent divides security and protocol processing into two segments: the PUC which requires security reconfiguration and is transferred to the target eNB, and the SUC which maintains existing security context and continues operating at the source eNB. This segmentation allows security updates without interrupting user-plane transmission.
Solution Approach 2:
The target eNB is pre-configured with the necessary security context and protocol parameters before the handover is executed. The source eNB transfers the PUC context to the target eNB in advance, allowing the target to be ready to immediately assume the primary role without requiring security reconfiguration during the actual handover moment.
3Reliability
If frequent handovers are performed to maintain coverage in microcellular networks, then coverage continuity is improved, but signaling storm in core network occurs
Solution Approach 1:
The patent extracts the user-plane data transmission function from the handover signaling process by maintaining it at the source eNB through the SUC. This extraction allows the PCell to be relocated without triggering repeated core network signaling, as the user-plane continuity is maintained independently of the control-plane handover signaling.
Solution Approach 2:
The patent performs a partial handover by transferring only the PUC to the target eNB while leaving the SUC at the source eNB. This partial action is sufficient to achieve coverage continuity and improve load balancing, but excessive full handovers with complete user-plane transfer are avoided, thereby reducing unnecessary core network signaling.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present application provides a method for user-plane operation, a user equipment, UE, and a storage medium. The method is applied to a UE during cellular network relocation and includes: in a downlink direction of one radio bearer, deciphering, by the UE, data packets received from a first node and a second node, the first node and the second node having different keys; reordering, by the UE, the deciphered data packets of the one radio bearer for transmission to an upper layer. The UE is connected with the first node and the second node simultaneously.