Vertical handoff is one of the most challenging issues in heterogeneous network environments. There are many researches on this issue, but they still have some drawbacks such as low efficiency of utilization of the wireless network resources and can not satisfy each application's requirements. This paper proposes a mechanism that takes each application into consideration. Every application can choose its own network interfaces by its requirements. The proposed scheme has the advantages of satisfying all the applications requests and simultaneously uses multiple interfaces to increase the utilization of interfaces. We measure the performance of applications under different networks to see if the network is suitable for the application.