Mobility is the most important feature of a wireless cellular communication system. The IEEE standard 802.16E-2005 provides enhancements to IEEE standard 802.16-2004 to support subscriber stations (SS) moving at vehicular speeds. Although the IEEE 802.16e standard proposes to tackle this problem, the disruption time (DT) of handover is still too long to overcome the maximum delay time of real-time services such as VoIP and video bit streaming. To deal with these problems, we propose to optimize the decision taking algorithm parameters Modulation/coding, Scanning Threshold and Base Station & Mobile Station Antenna gain. The performance of our decision taking algorithm is evaluated using OPNET simulations.