Design of optimum parameters for handover initiation in WCDMA

WCDMA handover algorithms employ signal averaging, hysteresis and the time-to-trigger mechanism to optimize the trade off between number of unnecessary handovers, reported events (system load) and handover delay time. We investigate optimal parameters for the WCDMA intra-frequency handover algorithm and the impact of each parameter on the system performance. The number of reporting events triggered for handover and handover delay are key performance measures in this paper. The study shows various tradeoffs between the parameters related to averaging, hysteresis and time-to-trigger. We have also discovered that the layer3 filter and time-to-trigger mechanism may cause negative effects on each other in some cases and there are optimum values, when used simultaneously.