Abstract
With the movement of mobile devices, in order to keep the best quality of service, mobile devices are required to carry seamlessly handoff. As a result, the vertical handoff in heterogeneous networks is becoming a hot research topic. This paper presents a CRI based vertical handoff algorithm. The algorithm maps parameters to area between 0 and 1 in fuzzy controller, which improves the intelligence of vertical handoff. Our simulation results have proved that the algorithm reduces unnecessary handoff frequencies, and improves the efficiency of vertical handoff.