5G Handover QFI Length Adaptation for RAN Compatibility
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Solution Overview
Problem
Current 5G wireless communication systems face challenges in ensuring data transmission continuity when a terminal device is handed over between radio access network (RAN) devices with different Quality of Service (QoS) flow identifier (QFI) support capabilities, as existing solutions fail to adapt QFI lengths appropriately.
Innovation Solution
The method involves the source RAN device sending a handover request to the target RAN device with QFI length information, performing admission control based on both devices' capabilities, and adapting the QFI length to ensure compatibility, thereby ensuring continuous data transmission by using a QFI supported by the target RAN device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the source RAN device uses a 10-bit QFI for data transmission, then the QoS flow identification capability is improved, but the compatibility with target RAN devices that only support 6-bit QFI deteriorates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the QFI length based on the capabilities of the source and target RAN devices. When the source RAN device supports 10-bit QFI and the target supports only 6-bit QFI, the system transforms the 10-bit QFI into a 6-bit QFI through mapping relationships, thereby resolving the contradiction between high identification capability and compatibility.
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of a QFI mapping relationship that acts as a bridge between the source RAN device's 10-bit QFI and the target RAN device's 6-bit QFI. This mapping relationship is established through handover request messages and enables seamless translation without data loss.
2Reliability
If the QFI length is adapted during handover, then the data transmission continuity is improved, but the handover signaling complexity increases
Solution Approach 1:
The patent applies preliminary action by establishing the QFI mapping relationship during the handover preparation phase, before actual data transmission begins. The source RAN device includes the mapping relationship in the handover request message sent to the target RAN device, so that the target device is pre-configured with the necessary mapping information to maintain continuous data transmission.
Solution Approach 2:
The patent uses copying by including the QFI mapping relationship information in the handover request message from the source RAN device to the target RAN device. This copied information allows the target device to replicate the source device's QoS flow identification scheme while adapting to its own 6-bit QFI limitation.
Data Source
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AI summary
This patent application provides a handover method and apparatus. The method includes: sending, by a source radio access network RAN device, a handover request to a target RAN device, where the handover request includes information about a quality of service flow identifier QFI length configured by the source RAN device for a terminal device; performing, by the target RAN device, admission control; sending, by the target RAN device, a handover request acknowledgement to the source RAN device, where the handover request acknowledgement includes information about a QFI length configured by the target RAN device for the terminal device; sending, by the source RAN device, a handover command to the terminal device, where the handover command includes the information about the QFI length configured by the target RAN device for the terminal device; transferring, by the source RAN device, data to the target RAN device; receiving, by the target RAN device, access of the terminal device; sending, by the target RAN device, a path transfer request to a core network CN device, and receiving a path transfer acknowledgement from the CN device; and sending, by the target RAN device, a terminal device context release instruction to the source RAN device.