PDU Session Continuity for Mobile UEs in 5G Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G networks, user equipment (UE) moving between a local network and a telecommunications network faces challenges in maintaining continuous packet data unit (PDU) session connectivity, as existing solutions require creating a new PDU session and IP address, disrupting the previous connection, and do not support session mobility with non-allocated IP addresses.
Innovation Solution
The UE is configured to transmit a PDU session establishment request to the telecommunications network, including a reference to the session management context of the gateway device, allowing the network to establish a dedicated PDU session and maintain session continuity by branching out session management information, and when reconnecting to the local network, the UE initiates a PDU session modification request to nest the dedicated dataflow into the gateway device's established PDU session.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE creates a new PDU session when moving out of local network coverage, then connectivity can be reestablished, but the previous connection is broken and session continuity is lost
Solution Approach 1:
The UE performs preliminary actions by storing session management information (SMI) and a reference to the gateway device's session management context before moving out of coverage. This pre-stored information enables the UE to quickly reestablish connectivity without creating a completely new PDU session, thus maintaining session continuity while simplifying the reconnection process
Solution Approach 2:
The UE creates a copy of the session management information and reference to the gateway device's session management context, storing it locally. This copied information serves as a template that can be rapidly deployed when reconnecting to the telecommunications network, avoiding the need to renegotiate all session parameters and ensuring continuity without complex reconfiguration
2Productivity
If the gateway device maintains its PDU session to serve multiple devices, then resource utilization is improved, but individual UE mobility and session independence are limited
Solution Approach 1:
The session management information is segmented into two parts: the gateway device maintains the master session management context for resource allocation and multiple UEs, while each UE stores its own copy of the SMI and a reference to the gateway's context. This segmentation allows the gateway to efficiently manage resources for multiple devices while each UE retains independent mobility capability through its stored copy
Solution Approach 2:
The UE's stored session management information contains a nested reference to the gateway device's session management context. This nested structure allows the UE to maintain individual session state while being anchored to the gateway's master context, enabling both efficient gateway resource utilization and independent UE mobility through hierarchical session management
3Adaptability or versatility
If IP addresses are assigned by the gateway device rather than the 5GC, then local network autonomy is improved, but session mobility support in the telecommunications network is lost
Solution Approach 1:
The stored session management information acts as an intermediary that bridges the gateway device's IP address allocation system and the telecommunications network's session management requirements. By carrying the gateway-allocated IP address and session context reference in the stored SMI, the UE can present this information to the network, allowing the network to recognize and support mobility for addresses allocated by the autonomous gateway rather than requiring direct network allocation
Data Source
AI summary
One aspect of this disclosure pertains to a UE configured for controlling PDU session continuity in a system comprising a gateway device having an established PDU session with a telecommunications network storing a session management context for the gateway device relating to the established PDU session and providing a local network for a plurality of UEs using the established PDU session of the gateway device for data communication with a data network over the telecommunications network. The UE is configured to control the PDU session continuity by transmitting a PDU session establishment request to the telecommunications network to establish a dedicated PDU session with the telecommunications network, wherein the UE is configured to include in the PDU session establishment request at least one reference to the session management context for the gateway device stored in the telecommunications network. Reversely, the UE may be configured to transmit an access request to the gateway device, wherein the UE is configured to include in the access request at least one reference to a session management context of a dedicated PDU session of the UE in the telecommunications network to nest at least one dataflow into the session management context of the established PDU context of the gateway device.