MBS Session Context Forwarding for Inactive UE Continuity
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Solution Overview
Problem
The existing 4G MBMS technology limits UE reception continuity to static target cells and only allows two states: connected and idle, failing to support in-active UEs under the 5G NR architecture for multimedia broadcast services.
Innovation Solution
A method for MBS service data communication that allows UEs in an in-active state to trigger a new MBS context establishment process at a 5G RAN target node, utilizing common forwarding channels and/or N3 channels to ensure seamless MBS service continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the existing 4G MBMS technology is used with static target cells and only connected/idle states, then the system complexity is low, but the MBS service continuity for in-active UEs cannot be ensured
Solution Approach 1:
The patent introduces dynamic state transitions for UEs, allowing transitions between connected, idle, and in-active states. The in-active state is specifically designed to maintain MBS service context while consuming minimal resources, enabling service continuity without requiring full connection establishment. This dynamic state management resolves the contradiction by adding flexibility to UE states while maintaining systematic complexity control through standardized state transition procedures.
Solution Approach 2:
The patent segments the MBS service delivery mechanism into multiple independent components: MBS session context establishment, MBS data forwarding channels, and state management procedures. By separating these functions, the system can maintain service continuity for in-active UEs through context forwarding without requiring complete system reconfiguration, thus improving reliability while controlling complexity growth.
2Reliability
If MBS session context is established at target cell for mobile UEs, then the MBS service continuity is improved, but the signaling overhead and establishment time increase
Solution Approach 1:
The patent implements preliminary action by establishing MBS session context in advance at the source cell before UE mobility occurs. When a UE moves to a target cell, the pre-established context can be quickly forwarded and activated, significantly reducing the context establishment time compared to creating context from scratch at the target cell. This preliminary preparation resolves the time loss while maintaining service continuity.
Solution Approach 2:
The patent introduces the source cell as an intermediary that facilitates rapid context transfer to the target cell. The source cell maintains the MBS session context and can quickly forward it to the target cell upon detecting UE mobility, acting as a bridge that reduces the time required for context establishment at the target cell while ensuring service continuity.
3Productivity
If common forwarding channels are used for MBS data transmission, then the resource utilization is improved, but the channel management complexity increases
Solution Approach 1:
The patent makes the common forwarding channel a universal resource that serves multiple functions: it can transmit MBS data for in-active UEs, support inter-cell forwarding, and maintain service continuity across different UE states. By designing the channel with multi-functionality, the system improves resource utilization without proportionally increasing management complexity, as the same channel infrastructure handles diverse traffic types through standardized procedures.
Data Source
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AI summary
The present application provides an MBS data transmission method, a network side apparatus, and a device. The method comprises: obtaining, for a UE which moves to a target cell and is in a deactivated state, MBS session context related information from a source cell by sending a context request message to the source cell, and after the target cell establishes an MBS session context, performing MBS data transmission. The solution provided by the present application solves the existing problem that the MBS service transmission continuity cannot be ensured for a UE in a deactivated state.