QFI Mapping for Multicast Handover Without MBMS Support
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Solution Overview
Problem
Ensuring continuity of multicast/broadcast services during handover of a terminal device from an access network device supporting multicast/broadcast functions to one that does not, is a challenge in 5G communication systems.
Innovation Solution
Implementing a data transmission method involving the use of end markers and QoS flow remapping to manage handover of multicast services, ensuring seamless service continuity by distinguishing between individual terminal devices and their associated multicast sessions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If data is transmitted using a single antenna port, then device complexity is reduced, but channel quality deteriorates when the channel is time-varying or frequency-selective
Solution Approach 1:
The patent segments the transmission process by dividing data into multiple code blocks and assigning each to different antenna ports for parallel transmission. This segmentation allows the system to exploit spatial diversity while maintaining manageable complexity at each transmission node.
Solution Approach 2:
The patent implements a universal transmission framework that can operate in multiple modes: single-antenna port mode for simplicity and multi-antenna port mode for enhanced reliability. The same base transmission structure adapts to different channel conditions, providing multi-functionality across varying operational requirements.
2Reliability
If multiple antenna ports are used for parallel data transmission, then channel quality and reliability are improved, but device complexity increases
Solution Approach 1:
The patent uses copying by transmitting identical or redundant data copies through multiple antenna ports simultaneously. This allows the receiver to combine signals from different ports, improving reliability through diversity gain while keeping each individual transmission path simple and manageable.
Solution Approach 2:
The patent transitions from single-dimension (single antenna) to multi-dimension (multiple antennas) transmission by exploiting the spatial dimension. Data is transmitted across multiple spatial paths, and the receiver combines these spatially-diverse signals, effectively adding a spatial dimension to enhance reliability without proportionally increasing complexity at each node.
3Productivity
If code block segmentation is implemented for parallel transmission, then transmission efficiency is improved, but processing complexity increases
Solution Approach 1:
The patent segments the overall data transmission task into multiple independent code blocks that can be processed and transmitted in parallel. Each code block is handled by a specific antenna port, enabling simultaneous transmission and improving overall throughput while keeping individual processing tasks manageable.
Solution Approach 2:
The patent performs preliminary actions by pre-segmenting data into code blocks and pre-assigning them to specific antenna ports before transmission. This preliminary organization enables efficient parallel processing and transmission, improving productivity while distributing complexity across multiple independent processing streams rather than one complex sequential process.
Data Source
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AI summary
This application provides a data transmission method and apparatus. The method includes: A source access network device receives an end marker from a core network device through a transmission tunnel of a PDU session of a first terminal device, where the PDU session is associated with a first multicast/broadcast service; and in response to the end marker, the source access network device determines, based on the association between the PDU session and the first multicast/broadcast service, that the end marker acts on the first multicast/broadcast service of the first terminal device, to stop sending data of the first multicast/broadcast service to a target access network device through a forwarding tunnel of the first terminal device.