IAB Donor Handover Using Context Retention to Cut Signaling
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Solution Overview
Problem
In scenarios of inter-donor topology adaptation in IAB networks, the conventional method of removing and reestablishing context for terminal devices during IAB-node migration causes service interruption and increased signaling and latency due to the need for full context transmission over wireless backhaul.
Innovation Solution
Retain and reuse context information associated with the communication interface between the migrating IAB-node and the source IAB-donor for communication with the target IAB-donor, minimizing the need for full reestablishment and reducing signaling over Xn and F1 interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If context information is removed and reestablished during IAB-node migration, then communication reliability is ensured through full context transmission, but service interruption time and signaling latency increase
Solution Approach 1:
The target IAB-donor retrieves context information from the source IAB-donor before the IAB-node actually migrates. This preliminary retrieval of context information allows the target donor to be prepared for the handover, reducing the service interruption time when the migration occurs while ensuring communication reliability through complete context information.
2Reliability
If full context information is transmitted over wireless backhaul during migration, then communication reliability is maintained, but signaling overhead and latency increase
Solution Approach 1:
The patent extracts the context information retrieval process from the wireless backhaul path and moves it to the wired connection between IAB-donors. By retrieving context information directly between donors through wired connections rather than transmitting it over the wireless backhaul, the signaling overhead and latency are significantly reduced while maintaining communication reliability.
3Loss of time
If context information is retained and reused during inter-donor mobility, then signaling latency is reduced, but device complexity increases due to context management requirements
Solution Approach 1:
The source IAB-donor acts as an intermediary that stores and provides context information to the target IAB-donor during migration. This intermediary approach allows the target donor to obtain complete context information without the IAB-node needing to manage complex context retention and transmission processes, reducing signaling latency while managing device complexity through centralized context management at the donor level.
Data Source
AI summary
Embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable media for communication during inter-donor topology adaptation. A first device transmits, to a second device, first information about a first communication interface between the first device and a third device, receives, from the second device, an indication that context information associated with at least one fourth device and the first communication interface is retained, and uses the context information in communication via a second communication interface between the first device and the second device. The second device receive the first information, transmit, to the third device, a request for obtaining the context information, and receive the context information from the third device. In this way, reestablishment procedure can be simplified, and signaling over Xn interface, F1 interface and wireless backhaul can be minimized Further, latencies and service break for the terminal devices at the change of the IAB-donor can be reduced.