Handover Control via Interference Coordination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional handover processes in cellular mobile communication systems often fail or result in the ping-pong handover phenomenon due to interference from neighboring cells, leading to communication disruptions and increased system load.
Innovation Solution
The solution involves controlling the transmission of downlink signals from target base stations during the handover process by stopping the transmission of downlink signals from the target cell base station when the received power difference exceeds a predetermined threshold, allowing for a reliable handover without interference and preventing ping-pong handovers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If downlink signals are transmitted from target base station during handover determination, then spectral efficiency is improved, but handover reliability deteriorates due to interference
Solution Approach 1:
The source base station determines handover start determination timing in advance and transmits this timing information to the target base station before the actual handover occurs. The target base station then suspends downlink signal transmission during this predetermined period, ensuring that the handover determination process can be performed without interference while maintaining a clear timeline for when transmission should resume.
2Device complexity
If handover is performed without controlling target cell transmission, then system load is reduced, but ping-pong handover phenomenon occurs
Solution Approach 1:
The source base station continuously monitors the received power difference between the target cell and source cell, and based on this feedback, determines when to initiate handover start determination timing. When the power difference exceeds a threshold, the source base station triggers the interference coordination mechanism, creating a closed-loop control system that adapts to changing channel conditions and prevents unnecessary ping-pong handovers.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A base station, a mobile communication system and a handover control method are provided, which are capable of preventing a handover failure and a ping-pong handover phenomenon which are caused by an interference from a neighboring cell to a serving cell. When a received power difference (S2 - S1) between a received power S2 from a neighboring second base station, which is fed back from a mobile station, and a received power S 1 from first base station, becomes larger than a predetermined threshold value, the first base station to which the mobile station is connected requests the second base station to stop a transmission of a downlink signal including at least one of a data signal and a control signal. In response to the transmission-stop request, the second base station performs a determination of a radio resource in which the transmission of the downlink signal is to be stopped and a notification of the radio resource to the first base station, and stops a transmission of a downlink signal. The first base station allocates the radio resource notified from the second base station or a radio resource partially including the notified radio resource, as a radio resource used for the downlink signal to the mobile station.