5GS Interworking Status Indicator for EPS to 5G Mobility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current protocols for 5GS interworking in EPS networks fail to provide necessary information for network nodes like MME or gateway nodes, leading to improper functioning during mobility from EPS to 5GS, resulting in hanging PDN connections and misbehavior in target eNBs due to lack of 5GS interworking status and NR restrictions.
Innovation Solution
The proposed solution involves storing and transmitting the 5GS interworking status and NR restrictions between source and target MMEs through context requests and relocation messages, ensuring accurate decision-making during inter-MME mobility and handover procedures, and updating 5GS interworking status in the network to avoid resource wastage and signaling errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing protocols are used for 5GS interworking in EPS networks, then network nodes can function with basic mobility support, but network nodes cannot function properly due to lack of information on updated 5GS interworking status
Solution Approach 1:
The source MME proactively includes the 5GS interworking status indicator in the context response message before the target MME needs to make mobility decisions. This preliminary provision of information ensures that the target MME has accurate 5GS interworking status data available when processing handover or relocation requests, preventing information loss during inter-MME mobility procedures
Solution Approach 2:
The system implements a feedback mechanism where the source MME continuously maintains and updates the 5GS interworking status indicator based on UE network capability and subscription data, and feeds this information back to the target MME through context transfer messages. This feedback loop ensures that the 5GS interworking status information remains current and accurate across MME transitions
2Reliability
If 5GS interworking status information is not transmitted between MMEs, then signaling overhead is reduced, but hanging PDN connections and misbehavior in target eNBs occur
Solution Approach 1:
The invention extracts the essential 5GS interworking status information from the complex UE context data and isolates it as a distinct indicator that can be independently transmitted. By separating this critical status information from the full context transfer payload, the solution provides necessary reliability data without proportionally increasing overall message complexity
Solution Approach 2:
The solution changes the parameter representation by introducing a compact indicator format for 5GS interworking status rather than transmitting complete UE capability and subscription data. This parameter transformation maintains reliability while controlling complexity through efficient data representation
3Reliability
If 5GS interworking status is not updated during inter-MME mobility, then signaling messages remain simple, but network nodes cannot function properly due to outdated information
Solution Approach 1:
The source MME prepares and includes the current 5GS interworking status indicator in the context response message before the target MME needs to execute mobility procedures. This preliminary update ensures that the target MME receives accurate, up-to-date information without requiring additional signaling exchanges during the handover process
Solution Approach 2:
The system maintains continuous availability of accurate 5GS interworking status information by ensuring it is included in context transfer messages during inter-MME mobility. This continuous information provision prevents functional disruptions and ensures uninterrupted network operation during handover transitions
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure discloses methods and devices for wireless communication. Specifically, a method performed by a first mobility management entity is provided. The method includes sending an indicator for a packet data network (PDN) connection to a second MME. The indicator indicates whether the PDN connection is allowed to be moved from an evolved packet system (EPS) to a fifth generation system (5GS).