AMF Entity Session Re-establishment Using SMF Identifier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G mobile communications, the efficiency of establishing PDU sessions is low due to the AMF entity's need to reselect an SMF entity and the inconsistency of UPF entities during session re-establishment, leading to suboptimal user plane optimization.
Innovation Solution
The method involves carrying identifier information in the session establishment connection request to ensure that the AMF entity forwards the request to the correct SMF entity, thereby avoiding the inefficiency of reselecting SMF and UPF entities, and optimizing the user plane by selecting an appropriate UPF entity based on location and quality of service.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the AMF entity forwards the session establishment connection request to a newly selected SMF entity, then the session can be re-established, but the processing efficiency is reduced due to the additional SMF reselection process
Solution Approach 1:
The AMF entity performs preliminary action by selecting and determining the target SMF entity before the session re-establishment process begins. The AMF entity stores the correspondence between the PDU session identifier and the SMF entity identifier in advance, so when the connection request arrives, the target SMF entity is already identified, eliminating the need for reselection and improving processing efficiency
2Adaptability or versatility
If the AMF entity reselects an SMF entity when forwarding the first message, then a new SMF entity can be assigned, but the UPF selection becomes inconsistent and user plane optimization cannot be ensured
Solution Approach 1:
The system implements feedback by including the SMF entity identifier in the session establishment connection request message that the UE sends to the AMF entity. The AMF entity uses this feedback information to identify the original SMF entity that selected the UPF, ensuring that the same SMF entity handles the re-established session and maintains consistent UPF selection for user plane optimization
Data Source
Figure 1a
Figure 1b
Figure 2a~2b
AI summary
Embodiments of the present invention relate to the field of communications technologies, and in particular, to a method, an apparatus, and a system for establishing a session, to resolve a problem in the prior art that efficiency is low because an AMF entity needs to reselect an SMF entity when forwarding a first message. The method includes: receiving, by a mobility management function AMF entity, a first message sent by user equipment UE, where the first message carries identifier information, the identifier information is used to instruct the AMF entity to send the first message to a session management function SMF entity, and the first message is used to instruct the SMF entity to re-establish a session with the UE based on the identifier information by using a first user plane function UPF entity; and sending, by the AMF entity based on the identifier information, the first message to the SMF entity associated with the identifier information. The embodiments of the present invention are applied to a system for establishing a session.