Mobile IAB Group RRC Reestablishment for Inter-Donor Migration
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing group Radio Resource Control (RRC) reestablishment in mobile Integrated Access and Backhaul (IAB) nodes, particularly during inter-donor migration, leading to issues such as interference, signaling overhead, and performance optimization.
Innovation Solution
A computing apparatus and method for IAB nodes that transmit a first group common indication to connected UEs, followed by a success indication upon successful RRC reestablishment, and a second indication for failure, enabling coordinated actions by UEs and donor centralized units (CUs) to manage group mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual RRC reestablishment is performed for each UE during IAB node migration, then connection reliability is maintained, but signaling overhead increases and reestablishment time is extended
Solution Approach 1:
The patent combines multiple individual RRC reestablishment procedures into a single group RRC reestablishment process. The IAB node initiates one reestablishment procedure that applies to all connected UEs simultaneously, rather than processing each UE individually. This merging approach maintains connection reliability for all UEs while significantly reducing the total reestablishment time and signaling overhead.
Solution Approach 2:
The patent segments the reestablishment process into distinct phases: a first phase where the IAB node transmits a group common indication to all UEs about the upcoming group reestablishment, and a second phase where individual success or failure indications are transmitted. This segmentation allows UEs to prepare collectively while maintaining the ability to handle individual outcomes, resolving the contradiction between efficiency and reliability.
2Loss of time
If group RRC reestablishment is implemented, then signaling overhead is reduced and reestablishment time is shortened, but interference mitigation becomes more challenging
Solution Approach 1:
The patent implements preliminary action by transmitting a group common indication to all UEs before the actual group RRC reestablishment occurs. This advance notification allows UEs to prepare their receivers and suspend data transmissions proactively, reducing the risk of interference during the transition. The preliminary action ensures that when the reestablishment occurs, all UEs are synchronized and ready, minimizing harmful interference effects.
3Object-affected harmful factors
If individual RRC reestablishment procedures are used, then interference mitigation is easier, but signaling overhead increases and system complexity increases
Solution Approach 1:
The patent introduces an intermediary mechanism - the group common indication message - that mediates between the IAB node and multiple UEs. This single intermediary message replaces numerous individual signaling exchanges, reducing system complexity while maintaining coordinated control. The intermediary approach allows the system to manage group reestablishment with simpler signaling compared to handling each UE individually, while still providing the coordination needed for effective interference mitigation.
Data Source
AI summary
Group RRC reestablishment in mobile IAB nodes is disclosed. In an embodiment, the IAB node is configured to: in response to a trigger event associated with a group RRC reestablishment with a target donor CU, transmitting a first group common indication to all of a plurality of UEs that are connected to the IAB node; and in response to success of the group RRC reestablishment, transmitting a success indication to the plurality of UEs.