Inter-system UE Policy for 5GS-EPS Handover Continuity
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Solution Overview
Problem
Current communication systems face challenges in ensuring continuity of traffic processing for user equipment (UE) during handovers between 5GS and EPS systems, as the URSP policy is primarily used in the 5GS system, and there is a lack of clarity on how UE is bound to applications across these systems.
Innovation Solution
Implementing an inter-system policy method that allows UE to use different UE policies for traffic processing in the 5GS and EPS systems, ensuring continuity by applying specific UE policies to each system, including the use of DCN-ID and S-NSSAI mapping, and configuring rules for seamless handovers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single URSP policy is used in 5GS system, then policy management is simplified, but traffic processing continuity during handover to EPS system cannot be ensured
Solution Approach 1:
The patent segments the unified URSP policy into separate UE policies for different systems (5GS and EPS). The network configures distinct UE policies for each system, allowing independent optimization and ensuring that traffic processing can continue using the appropriate policy for the target system during handover, thus resolving the contradiction between simplified management and continuity assurance.
Solution Approach 2:
The patent implements dynamic policy selection based on the current system context. The UE dynamically switches between 5GS UE policy and EPS UE policy according to which system it is currently connected to, enabling flexible adaptation to different network environments while maintaining traffic processing continuity during handovers.
2Reliability
If different UE policies are configured for 5GS and EPS systems, then traffic processing continuity during handover is ensured, but policy configuration complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring separate UE policies for both 5GS and EPS systems before handover occurs. The network configures the 5GS UE policy and EPS UE policy in advance, so that when handover happens, the UE can immediately switch to the pre-configured appropriate policy without complex real-time decision-making, reducing the perceived complexity during operation.
Solution Approach 2:
The patent introduces the TAU (Tracking Area Update) procedure as an intermediary mechanism that triggers policy switching during handover. The TAU process acts as a mediator that automatically handles the transition between different UE policies based on the target system type, simplifying the overall policy management by providing a standardized trigger point for policy selection.
3Ease of manufacture
If URSP policy is only used in 5GS system, then policy formulation is straightforward, but application binding clarity is lost during EPS handover
Solution Approach 1:
The patent makes the UE policy universal across multiple systems (both 5GS and EPS) by configuring separate but analogous policies for each system. The UE policy structure and functionality are designed to work in both 5GS and EPS contexts, ensuring that application binding information is preserved and applicable regardless of which system the UE is connected to, thus preventing information loss during handover.
Data Source
AI summary
A method includes: using a first UE policy applied to a first system when traffic is processed in the first system; and using a UE policy applied to a second system when traffic is processed in the second system, where the UE policy applied to the second system and the first UE policy applied to the first system are applied to same UE.