A New Method for Vertical Handoff between WLANs and UMTS in Boundary Conditions

We propose a new vertical handoff method in which the number of signaling and registration processes is lowered as a result of reduced utilization of home agent and correspondent nodes while users are mobile. Throughput performance of the integrated network is improved by reducing handoff delays and packet losses. Special conditions such as boundary condition also considered. Performance and delay evaluations which done by ns-2 are presented to demonstrate the effectiveness of the proposed scheme.