4G to 5G Handover S-NSSAI Mapping for Seamless Service Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a mechanism that allows applications using a communication service in a 4G network to seamlessly transition to a 5G network, as current technologies do not efficiently associate applications with the necessary Single Network Slice Selection Assistance Information (S-NSSAI) during handovers from 4G to 5G, leading to potential service disruptions.
Innovation Solution
A method where the 4G communication network provides the mobile terminal with the necessary S-NSSAI information for the 5G network slice during the PDU session establishment, allowing the UE to maintain the mapping of EPS bearers to 5G S-NSSAI, ensuring seamless handover and continued service without NAS-level communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mobile terminal moves from 4G to 5G network, then the terminal can access 5G communication services, but the application cannot properly associate with the 5G network slice without S-NSSAI information
Solution Approach 1:
The 4G core network performs preliminary actions by determining and transmitting the S-NSSAI to the mobile terminal before the actual handover to 5G occurs. During the PDN connection establishment in 4G, the MME determines the S-NSSAI based on stored mapping information and sends it to the UE, so that when the terminal moves to 5G, the S-NSSAI is already available for immediate network slice association, ensuring service continuity without requiring NAS-level communication during handover
2Reliability
If the 4G network transmits S-NSSAI information to the mobile terminal, then the terminal can maintain session continuity during handover, but additional signaling and processing are required
Solution Approach 1:
The MME acts as an intermediary by maintaining a mapping between EPC DCN-ID/APN and 5GC DNN/S-NSSAI. During PDN connection establishment, the MME determines the S-NSSAI based on the stored mapping and transmits it to the UE through existing signaling procedures. This intermediary approach enables session continuity during handover by preparing the S-NSSAI information in advance through the 4G core network, avoiding the need for complex NAS-level communication during the actual handover process
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to one embodiment, a method for providing a communication service is described comprising a mobile terminal running an application, a first communication network providing a communication service to the application using a bearer between the mobile terminal and a core network of the first communication network; the first communication network transmitting to the mobile terminal an identification of a core network slice of a second communication network, wherein the core network slice is to be used when providing the communication service to the application by means of the second communication network; and the mobile terminal using the communication service based on the core network slice of the second communication network.