NTN Conditional Handover Across Multi-PLMN Coverage Areas
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Solution Overview
Problem
Existing communication systems in non-terrestrial networks (NTN) face challenges in performing conditional handover (CHO) when a candidate target cell supports multiple public land mobile networks (PLMNs) and/or access and mobility management functions (AMFs), leading to handover reliability issues.
Innovation Solution
A communication method and apparatus that enables a terminal device to determine a target cell, PLMN, and/or AMF based on received information and its current location, using CHO configuration information to select a suitable cell from among those supporting multiple PLMNs and/or AMFs, and sends a message to the target network device upon successful handover to optimize resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a candidate target cell supporting multiple PLMNs and/or AMFs is configured for conditional handover, then the coverage area is expanded and service continuity is improved, but the complexity of handover decision-making increases and handover reliability decreases
Solution Approach 1:
The patent segments the candidate target cell into multiple service areas, each associated with specific PLMN and AMF information. The terminal device determines which service area it is located in and selects the corresponding PLMN/AMF configuration, thereby resolving the complexity of handover decision-making in multi-PLMN cells while maintaining expanded coverage.
2Adaptability or versatility
If a candidate target cell supporting multiple PLMNs and/or AMFs is configured for conditional handover, then service continuity across multiple operators is improved, but the device complexity for selecting the correct PLMN and AMF increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring multiple sets of PLMN and AMF information along with their corresponding service area identifiers in the conditional handover configuration. The terminal device performs preliminary location determination based on service area information before executing handover, thereby reducing the complexity of real-time decision-making while ensuring service continuity across multiple operators.
3Reliability
If conditional handover is performed in NTN cells with large coverage, then handover reliability is improved, but the difficulty of determining the correct target PLMN and AMF increases
Solution Approach 1:
The patent introduces service area information as an intermediary element that links the terminal device's location to the appropriate PLMN and AMF configuration. The terminal device determines its location based on service area identifiers (such as longitude/latitude ranges) and uses this intermediate information to select the correct target PLMN and AMF, thereby simplifying the determination process in large-coverage NTN cells while maintaining handover reliability.
Data Source
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AI summary
This application discloses a communication method and apparatus, to provide a CHO mechanism applied when an NTN cell that covers geographical areas of a plurality of countries or service areas of a plurality of operators is configured as a candidate target cell of a terminal device. The method includes: In a CHO scenario, if first PLMN information and/or first AMF information of a candidate target cell correspond/corresponds to first CHO configuration information and first area information, and second PLMN information and/or second AMF information of the candidate target cell correspond/corresponds to second CHO configuration information and second area information, a terminal device may determine a target cell, and target PLMN information and/or target AMF information based on first information received from a source network device and an area in which the terminal device is currently located, to improve handover reliability.