Uplink Synchronization for Seamless Cell Handover
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Solution Overview
Problem
The frequent handovers of user equipment (UE) between small-cell and macro base stations result in data transmission interruptions and poor user experience due to the need for dual connectivity, which requires carrier aggregation capabilities and increased power consumption.
Innovation Solution
The UE maintains uplink synchronization with a first cell while performing data transmission on a second cell, allowing for seamless handover to the first cell without a random access process, reducing data transmission interruptions and improving user experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dual connectivity technology is used to resolve frequent handovers, then handover frequency is reduced, but device complexity and power consumption increase due to carrier aggregation requirements
Solution Approach 1:
The patent applies preliminary action by pre-establishing uplink synchronization between the UE and the first cell (macro base station) before handover occurs. The UE maintains uplink synchronization with the first cell while connected to the second cell (small-cell base station), so that when handover is needed, the UE can immediately switch to the first cell without performing random access, thereby avoiding frequent handovers and their associated disruptions.
2Reliability
If dual connectivity with macro base station as master eNodeB is used, then handover stability improves, but power consumption increases due to continuous communication requirements
Solution Approach 1:
The patent applies preliminary action by pre-establishing uplink synchronization between the UE and the first cell (macro base station) before handover occurs. The UE maintains uplink synchronization with the first cell while connected to the second cell (small-cell base station), so that when handover is needed, the UE can immediately switch to the first cell without performing random access, thereby avoiding frequent handovers and their associated disruptions.
3Device complexity
If traditional handover process is used, then device complexity is reduced, but data transmission interruption time increases due to random access requirement
Solution Approach 1:
The patent applies preliminary action by pre-establishing uplink synchronization between the UE and the first cell (macro base station) before handover occurs. The UE maintains uplink synchronization with the first cell while connected to the second cell (small-cell base station), so that when handover is needed, the UE can immediately switch to the first cell without performing random access, thereby avoiding frequent handovers and their associated disruptions.
Data Source
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AI summary
Embodiments of the present invention relate to a communication method and a device. The method includes: receiving instruction information, where the instruction information is used to instruct user equipment to establish and/or maintain uplink synchronization of the user equipment with a first cell controlled by a first base station; when the user equipment is in uplink synchronization with the first cell according to the instruction information, the user equipment is in a radio resource control RRC connected state, and a serving cell of the user equipment is a second cell controlled by a second base station; and handing over the user equipment from the second cell to the first cell that is in uplink synchronization with the user equipment, and performing communication based on the first cell. By means of the communication method and the device provided in the embodiments of the present invention, a time of data transmission interruption caused by a handover of UE between cells is reduced.