Inter-CU Cell Switching Using Preconfigured Mobility Signaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Intra-centralized unit (CU) Layer 1/Layer 2 (L1/L2) triggered mobility (LTM) is limited to mobility between cells within the same Next Generation Node B (gNB) or CU, restricting its application opportunities.
Innovation Solution
A method for cell switching that enables mobility between the same CU or different CUs, involving a network node initiating a request for cell switch configurations, receiving acknowledgments, and transmitting configurations to user equipment (UE) for seamless cell switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If intra-CU LTM is used for cell switching, then mobility latency is reduced, but the applicability is limited to cells within the same CU
Solution Approach 1:
The patent extends the LTM mechanism to support inter-CU cell switching by enabling the source CU to directly communicate with and retrieve configuration information from the target CU. This multi-functionality allows the same LTM procedure to work for both intra-CU and inter-CU scenarios, significantly expanding the applicability range while maintaining the low-latency advantage.
Solution Approach 2:
The source CU acts as an intermediary that coordinates the cell switching process between the UE and the target CU. By having the source CU directly obtain configuration information from the target CU through inter-CU communication, the patent eliminates the need for UE involvement in configuration retrieval, enabling fast inter-CU switching similar to intra-CU LTM.
2Adaptability or versatility
If inter-CU cell switching is implemented, then mobility flexibility is enhanced, but signaling complexity between CUs increases
Solution Approach 1:
The patent employs preliminary action by having the source CU obtain the target cell's configuration information (such as physical channel configurations, resource allocations, and security parameters) before the actual cell switching occurs. This pre-retrieval of configuration data through inter-CU signaling reduces the signaling burden during the actual switching event, as the target CU does not need to send extensive configuration messages to the UE after switching.
Solution Approach 2:
The patent extracts the configuration information retrieval process from the UE and relocates it to the CU level. Instead of the UE needing to request and process configuration information from multiple CUs, the source CU directly extracts the necessary configuration data from the target CU. This extraction simplifies the overall signaling flow by consolidating configuration management at the network side.
3Speed
If configuration information is retrieved from target CU before switching, then switching speed is improved, but inter-CU communication overhead increases
Solution Approach 1:
The patent applies local quality by having the source CU request and receive only the specific configuration information needed for the target cell, rather than exchanging all possible configuration data. The inter-CU communication is optimized to transfer only relevant parameters such as physical channel configurations, resource allocations, and security settings specific to the target cell, minimizing the communication overhead while enabling fast switching.
Solution Approach 2:
The patent uses partial action by selectively retrieving only the necessary configuration information from the target CU before cell switching, rather than obtaining all possible configuration data. This selective retrieval includes only the critical parameters needed for immediate switching operation, reducing the volume of inter-CU communication while maintaining switching speed.
Data Source
AI summary
A method of cell switching and a first network node and a user equipment using the same method are provided. The method includes initiating a request message to request a cell switch related configuration for at least one candidate cell, wherein the at least one candidate cell belongs to a second network node. Receiving a request acknowledge message from the second network node, wherein the request acknowledge message comprises a first configuration for at least one accepted candidate cell. Transmitting a first message to the second network node to update information of the at least one accepted candidate cell. Transmitting a second configuration to a user equipment.