WLAN Termination U-Plane Relocation Without C-Plane
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Solution Overview
Problem
Current LTE-WLAN Aggregation (LWA) technologies face challenges in WLAN mobility, leading to increased signaling load and temporary service disruptions due to the need to change both user-plane and control-plane terminations during UE mobility, limiting flexibility and quality of experience.
Innovation Solution
The solution involves establishing a control-plane interface between a cellular radio access node and an anchor for non-cellular radio access nodes, allowing relocation of the user-plane interface during UE mobility while maintaining the control-plane interface, enabling seamless WLAN mobility across multiple APs without requiring new Xw-C connection negotiations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If both user-plane and control-plane terminations are changed during UE mobility between WLAN APs, then mobility is supported, but signaling load increases and service disruptions occur
Solution Approach 1:
The patent segments the WLAN termination function into two independent parts: control-plane termination (WT-C) and user-plane termination (WT-U). The control-plane interface remains anchored at the WLAN controller, while the user-plane interface can be dynamically relocated between different WLAN access points. This segmentation allows mobility to be handled at the user-plane level without triggering control-plane reconfiguration, thereby reducing signaling load and avoiding service disruptions during handovers.
2Adaptability or versatility
If both user-plane and control-plane terminations are changed during UE mobility, then mobility is supported, but service continuity is disrupted
Solution Approach 1:
By separating control-plane and user-plane terminations, the patent ensures that control-plane connectivity remains stable and continuous while user-plane resources can be switched between APs. The anchored control-plane interface maintains persistent signaling connections, preventing service disruptions during mobility events.
Solution Approach 2:
The control-plane interface is established and anchored in advance at the WLAN controller before mobility occurs. This preliminary establishment of a stable control-plane connection ensures that when user-plane relocation is needed, the control-plane framework is already in place to manage the transition smoothly, maintaining service continuity.
3Adaptability or versatility
If control-plane termination is relocated during UE mobility, then mobility is supported, but Xw-C connection negotiation is required
Solution Approach 1:
The patent segments the termination functions so that only the user-plane termination (WT-U) needs to be relocated during mobility, while the control-plane termination (WT-C) remains anchored at the original WLAN controller. This eliminates the need for time-consuming Xw-C connection negotiations, as the control-plane interface remains unchanged. User-plane relocation can occur rapidly without triggering control-plane reconfiguration procedures.
4Adaptability or versatility
If multiple WLAN APs are supported in a mobility set, then flexibility is improved, but device complexity increases
Solution Approach 1:
The patent enables multiple WLAN access points to be included in a mobility set by maintaining a single anchored control-plane interface that can manage multiple user-plane connections to different APs. The control-plane termination at the WLAN controller handles mobility management for multiple APs, while each AP maintains independent user-plane termination. This segmentation allows flexible multi-AP support without proportionally increasing control-plane complexity.
Solution Approach 2:
The anchored control-plane interface at the WLAN controller is designed to be universal, capable of managing user-plane connections to multiple different WLAN access points simultaneously. This multi-functional control-plane termination can handle mobility across any AP in the mobility set without requiring separate control-plane interfaces for each AP, thereby supporting multi-AP mobility with controlled complexity.
Data Source
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AI summary
A control-plane interface is established between a cellular radio access node and an anchor for at least first and second non-cellular radio access nodes (such as API and AP2); and thereafter during mobility of a user equipment (UE) from API to AP2, the anchor relocates a user-plane interface for a radio link allocated to the UE from API to AP2 while maintaining the established control-plane interface for the radio link. When implemented for LTE-WLAN Aggregation (LWA), the control-plane interface is Xw-C with a corresponding control plane wireless termination (WT-C), the user-plane interface is Xw-U with a corresponding user plane wireless terminations (WT-U); the cellular radio access node is an eNB, the APs belong to the anchor and have BSSs that belong to a same mobility set that is configured for the UE by the eNB; the anchor is the WT-C, and the APs are WT-Us.