A Dual-Soft-Handoff Scheme for Fast Seamless Roaming in WLAN

In recent years, wireless local area network (WLAN) has been deployed in many wireless applications. When the mobile node (MN) accesses different access points (AP), handoff latency may cause packet loss and result in serious problems in real-time applications. This paper proposes an efficient soft handoff scheme realized by dual-handoff. The MN maintains two active links to forward and backward APs respectively, and the handoffs are never simultaneous to ensure one data thoroughfare always existing. It achieves seamless data transmission during fast motion. Simulation results indicate that it´s at least feasible in WLAN while the MN moves at 120km/h.