Rapid progress in the research and development of wireless networking and communication technologies has created different types of wireless communication systems. Nevertheless, the integration of heterogeneous networks poses many challenges especially the problem of handover decision as resolving it influences mainly on the handover performance. In this paper, we introduce a handover decision algorithm based on Neyman-Pearson method and then we combine with Fast Mobile IPv6 protocol for mobility management. This combination enables an optimized and a seamless handover. In order to study the performance of our method, we choose to study two emerging technologies: WiFi based on IEEE 802.11e and Mobile WiMAX based on IEEE 802.16e standard. Numerical investigations illustrate that our proposed method enables a handover optimization in terms of (i) guaranteeing the quality of service parameters for different type of ongoing sessions during the handover, (ii) reducing handover latency and (iii) minimizing ping-pong effects.