DAPS Handover Source Cell Release Indication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual Active Protocol Stack (DAPS) handovers in wireless communication systems face delays and increased complexity due to the need for the UE to maintain connections with both the source and target cells, leading to potential radio link failures during subsequent handovers.
Innovation Solution
The proposed solution allows the UE to implicitly or explicitly release the source cell connection during a DAPS handover, enabling faster subsequent handovers by including an indication in the handover command to release the source cell connection, thus avoiding the need for a dedicated reconfiguration message.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE maintains connections with both source and target cells during DAPS handover, then connection reliability is improved, but handover delay and device complexity increase
Solution Approach 1:
The source cell connection is released in advance upon receiving the handover command from the target cell, before the actual handover is completed. This preliminary release action eliminates the need to maintain dual connections during the handover process, thereby reducing handover delay while ensuring connection reliability through the advance preparation of the release timing.
2Reliability
If the UE maintains connections with both source and target cells during DAPS handover, then connection reliability is improved, but device complexity increases
Solution Approach 1:
The source cell connection is released in advance upon receiving the handover command, before the handover is completed. This preliminary action simplifies the UE's connection management by eliminating the need to simultaneously maintain and manage dual active connections, thereby reducing device complexity while preserving connection reliability through proper timing of the release operation.
3Ease of operation
If a dedicated reconfiguration message is sent to release the source cell connection, then connection management is improved, but signaling overhead and handover delay increase
Solution Approach 1:
The source cell connection release indication is merged into the handover command message from the target cell. By combining the release instruction with the existing handover signaling, the patent eliminates the need for a separate dedicated reconfiguration message, thereby reducing signaling overhead and handover delay while maintaining proper connection management through the integrated indication.
4Ease of operation
If a dedicated reconfiguration message is sent to release the source cell connection, then connection management is improved, but signaling overhead increases
Solution Approach 1:
The source cell connection release indication is merged into the handover command message from the target cell. This consolidation combines multiple control functions into a single signaling message, thereby reducing the total quantity of signaling overhead transmitted over the air interface while ensuring proper connection management through the integrated release indication.
Data Source
AI summary
According to an example embodiment, a first target access node of a radio access network sends (910) a first handover command to a source access node serving a user equipment, UE, for transmission to the UE, the first handover command indicating a DAPS handover to a first target cell, served by the first target access node. Prior to the UE releasing the source cell for the DAPS handover, however, the first target access node determines (920) to perform a handover of the UE to a second target cell and transmits (930) a second handover command to the UE, the second handover command ordering a handover to the second target cell and including an explicit indication that the UE is to release the source cell upon receiving the second handover command.