The integration of wireless worldwide interoperability for microwave access network (WiMAX and Long Term Evolution (LTE) in an all IP based heterogeneous networks that require seamless mobility is predicated on enabling the connection and retrieval of data by a mobile user not mindful of the medium or technology used. This phenomenon facilitates freedom of movement while maintaining service continuity. However, the interoperability between multiple access technologies should be able to realize the vision of 4G technology and beyond to allow mobile user equipment (UE) to roam freely when intersecting the cell-boundaries of different network platforms without losing the service. To achieve such task, a proposed mobility management system designed to detect conditions of the network early enough and effect changes to handover parameters while maintaining the network connectivity is being highlighted. The proposed system investigates how the signal strength threshold (RSSTh) influences handover decision for a prioritized network with regards to distance and velocity. Computer simulation based on a designed algorithm for vertical handover optimization is being implemented to trigger the inter-radio access technology (RAT) handover for evaluating the performance of next generation wireless network systems. The results show that the prioritized network stand to be the preferred network as the UE is connected to it most of the time.