Cell Handover MAC Reset for BSR and HARQ Continuity
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Solution Overview
Problem
Existing cell handover methods in mobile communication systems result in service quality deterioration due to incomplete resetting of media access control (MAC) layer information, leading to disruptions in data transmission continuity.
Innovation Solution
A method for partial resetting of MAC layer information during cell handover, involving the cancellation of specific buffer status reports (BSRs) and hybrid automatic repeat request (HARQ) processes based on configuration information of source and target cell groups, ensuring valid BSRs and HARQ processes are maintained in the target cell group.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complete resetting of MAC layer information is performed during cell handover, then service quality is improved, but data transmission continuity is disrupted
Solution Approach 1:
The patent segments the MAC layer information resetting process by identifying and differentiating between valid BSRs/HARQ processes (those associated with target cell group logical channels) and invalid ones (those associated with source cell group only). This segmentation allows selective resetting, maintaining continuity for valid processes while clearing invalid ones, thus resolving the contradiction between service quality improvement and transmission continuity.
Solution Approach 2:
The patent applies local quality by treating different BSRs and HARQ processes differently based on their association with source or target cell group logical channels. Valid processes associated with target cell group channels maintain their state locally, while invalid processes are reset. This localized differentiation ensures service quality improvement without disrupting overall data transmission continuity.
2Duration of action of moving object
If partial resetting of MAC layer information is performed during cell handover, then data transmission continuity is improved, but service quality deteriorates
Solution Approach 1:
The patent employs feedback mechanisms where the terminal device determines the validity of each BSR and HARQ process based on configuration information from both source and target cell groups. This feedback loop ensures that only processes associated with target cell group logical channels are maintained, while others are reset. The feedback mechanism guarantees service quality by ensuring that maintained processes are indeed valid for the target cell group, thus resolving the contradiction between continuity and service quality.
3Loss of energy
If all triggered BSRs are canceled during cell handover, then resource wastage is prevented, but protocol stack processing continuity is disrupted
Solution Approach 1:
The patent applies partial action by selectively canceling only those BSRs that are associated with source cell group logical channels, while maintaining BSRs associated with target cell group logical channels. This partial cancellation prevents resource wastage for invalid BSRs while preserving protocol stack processing continuity for valid ones, thus resolving the contradiction between preventing resource wastage and maintaining processing continuity.
4Loss of energy
If all HARQ process data packets are deleted during cell handover, then resource wastage is prevented, but data transmission continuity is disrupted
Solution Approach 1:
The patent segments HARQ processes into valid and invalid categories based on their association with target cell group logical channels. Data packets in valid HARQ processes (those associated with target cell group channels) are preserved, while data packets in invalid HARQ processes (those associated with source cell group only) are deleted. This segmentation prevents resource wastage for invalid processes while maintaining data transmission continuity for valid ones, resolving the contradiction between preventing resource wastage and maintaining transmission continuity.
Data Source
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AI summary
Embodiments of this application provide a cell handover method and apparatus, and are applied to the communication field. The cell handover method includes: A terminal device receives a handover command from an access network device; based on configuration information of a source cell group and configuration information of a target cell group, cancels a triggered first buffer status report BSR and/or deletes a data packet corresponding to a first hybrid automatic repeat request HARQ process; and then performs handover to the target cell group based on the handover command. In embodiments of this application, a behavior of partially resetting information at a MAC layer by the terminal device can be specified, to improve continuity of data transmission during cell handover, so as to improve user experience.