4G-5G PDU Session Handover Prioritization for Lower Transfer Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The transfer of data connections between 4G and 5G communications systems is delayed due to the absence of an N26 interface, leading to failed handovers and increased delays in establishing packet data network connections, as existing methods fail to prioritize data connection channels that support interworking.
Innovation Solution
A method and device that prioritize the transfer of data connection channels, specifically PDU sessions, that are certain or uncertain to support transfer between 4G and 5G systems, ensuring seamless handover by selecting and prioritizing sessions based on network access manner and service continuity modes, thereby reducing transfer delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE sequentially transfers PDU sessions one by one from 5G to 4G, then the handover process can be completed, but the transfer delay increases significantly
Solution Approach 1:
The patent applies preliminary action by having the UE identify and mark PDU sessions suitable for handover before the actual transfer process. The UE determines which PDU sessions can be transferred based on network access manner and service continuity mode, preparing the handover list in advance. This preliminary identification enables more efficient sequential transfer and reduces overall delay by avoiding unnecessary re-attempts during the handover process.
2Productivity
If the UE transfers PDU sessions that do not support interworking, then the handover process fails, but the UE needs to re-initiate initial attach and retry transfer
Solution Approach 1:
The patent applies preliminary action by having the UE identify and mark PDU sessions suitable for handover before the actual transfer process. The UE determines which PDU sessions can be transferred based on network access manner and service continuity mode, preparing the handover list in advance. This preliminary identification enables more efficient sequential transfer and reduces overall delay by avoiding unnecessary re-attempts during the handover process.
Solution Approach 2:
The patent applies feedback by having the UE receive feedback information from the network about PDU session transfer capability. The UE uses this feedback to determine which PDU sessions should be included in the handover list and which should not. This feedback mechanism prevents the UE from attempting to transfer unsupported sessions, thereby avoiding failed handovers and subsequent re-attachment procedures.
3Adaptability or versatility
If the UE selects PDU sessions for transfer without prioritization, then all sessions are treated equally, but sessions with higher transfer priority are delayed
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different PDU sessions based on their specific characteristics. The UE determines transfer priority for each session based on its network access manner (e.g., internet, IMS, local area data network) and service continuity mode. Critical sessions requiring high priority are identified and transferred first, while less critical sessions are transferred subsequently. This localized differentiation ensures that time-sensitive sessions receive preferential treatment without compromising overall transfer flexibility.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Embodiments of this application disclose a method for transfer between communications systems and a related device, to preferentially transfer a second data connection channel in a first data connection channel, thereby reducing a delay of transferring a terminal device between different communications systems. The embodiments of this application provide a method for transfer between communications systems. The method includes: establishing at least one first data connection channel in a first communications system; selecting at least one second data connection channel from the at least one first data connection channel, where the second data connection channel is included in the first data connection channel, is a data connection channel that is certain to support transfer from the first communications system to a second communications system, and/or is a data connection channel that is uncertain whether to support transfer from the first communications system to the second communications system; and when the terminal device is transferred from the first communications system to the second communications system, preferentially transferring the second data connection channel to the second communications system.