A study on handover parameter optimization in LTE-A networks

Network controlled and UE assisted hard Handover (HO) procedure is adopted in 3GPP LTE-Advanced systems. Hysteresis Margin (HM) and A3offset are the major parameters based on which the entering condition of A3event is initiated. In order to mitigate the initiation of HO procedure due to momentary signal fading, persistence of A3event entering condition need to be verified for a period of Time-To-Trigger (TTT). These three parameters are configured by the base station (eNodeB) in the Measurement Configuration (MC) phase. In order to accomplish successful handover (HO), the impact of HM, A3offset along with TTT need to be analyzed. Hence in this research, the above analysis has been extended to different ISD for varying user velocity. From the simulation results obtained, it is found that i) as ISD increases, percentage of A3offset and HM combinations which results in HO success decreases and ii) smaller TTT holds good for larger ISD and vice versa.