PDN Connection Handling in LTE to 5G NR Mobility
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Solution Overview
Problem
Inter-system mobility between LTE and 5G networks poses challenges in maintaining seamless service continuity, particularly in handling PDN connections and PDU Session IDs during handovers between these systems.
Innovation Solution
The implementation of processes and communication methods that involve activating PDN connections, communicating PDU Session IDs, and managing EPS bearers to facilitate smooth handovers between LTE and 5G networks, including the use of specific messages and context responses to maintain service continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If inter-system mobility between LTE and 5G networks is implemented, then network versatility and service continuity are improved, but system complexity and difficulty of managing PDN connections and PDU Session IDs increase
Solution Approach 1:
The patent implements a unified mobility management framework where the same core network entities (MME, SMF) and signaling procedures handle both intra-system and inter-system mobility. The system uses universal PDU session concepts that work across both LTE and 5G NR, allowing the same architecture to serve multiple radio access technologies without requiring separate management systems for each technology.
Solution Approach 2:
The patent introduces the core network as an intermediary layer between the LTE and 5G NR radio access networks. The MME and SMF entities in the core network manage the translation and coordination of PDN connections and PDU sessions, abstracting away the complexity of inter-system handover from the user equipment. This intermediary approach allows seamless mobility while centralizing the complexity management in the network infrastructure.
2Reliability
If PDN connection management is maintained during handover between LTE and 5G, then service continuity is improved, but signaling overhead and processing time increase
Solution Approach 1:
The patent establishes PDN connections and PDU sessions in advance during the initial network attachment, so that when handover occurs, the data bearers are already configured and ready for immediate activation in the target system. The core network pre-allocates session resources and prepares the signaling context, enabling rapid service resumption without time-consuming connection re-establishment during the actual handover event.
Solution Approach 2:
The patent maintains active PDN connection contexts and PDU session states throughout the handover process, ensuring that data transmission can continue uninterrupted. The core network entities retain the session information and quickly re-establish data bearers in the target system, minimizing the interruption time and maintaining the continuity of useful data transmission action throughout the mobility event.
3Measurement precision
If context information is exchanged between LTE and 5G network entities, then mobility management accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent extracts and transfers only the essential context information required for mobility management between LTE and 5G network entities. The signaling messages contain specifically selected parameters such as PDU session IDs, QoS profiles, and bearer contexts that are critical for maintaining service continuity, while omitting redundant or unnecessary data. This selective extraction approach ensures accurate mobility management with minimized signaling overhead.
Data Source
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AI summary
A long-term evolution (LTE) network for handling mobility from the LTE network to a new radio (NR)/fifth generation (5G) network comprises a storage device for storing instructions and a processing circuit coupled to the storage device. The processing circuit is configured to execute the instructions stored in the storage device. The instructions comprise activating a Packet Data Network (PDN) connection with a communication device; communicating a Protocol Data Unit (PDU) Session identity/identifier (ID) for the PDN connection with the communication device; communicating data via an evolved packet system (EPS) bearer associated to the PDN connection with the communication device; receiving a context request for the communication device from the NR/5G network; and transmitting a context response comprising a context of the communication device to the NR/5G network in response to the context request.