The next-generation of wireless systems represents a heterogeneous environment with different access networks technologies that differ in bandwidth, latency or cost. The most challenging problem is the seamless vertical mobility across heterogeneous networks. In order to improve the accuracy and efficiency of the vertical handover for such heterogeneous networks, this paper proposes a novel handover network decision mechanism with Q
S provision based on analytic hierarchy process (AHP) and grey relational analysis (GRA) methods. We have successfully simulated and tested our approach using the OPNET simulation tool. The simulation results revealed that the proposed algorithm can not only work efficiently for 3G (TD-SCDMA), WLAN (IEEE 802.11),4G system but also reduce the complexity of implementation significantly.