Mobility-based traffic offload from WiMAX to WLAN

Decisions for vertical handover in heterogeneous mobile and wireless networks are very important because they impact the QoS of the mobile users and they are also dependent upon the mobility. Choosing the right radio interface at a given moment when mobile terminal has more than one available wireless or mobile network can be based on various factors beside signal strength. In this paper we propose and implement traffic offload algorithm which uses mobile nodes speed and session´s priority, real-time or non-real-time, as factors for vertical handover decision from WiMAX to WLAN. We use IEEE 802.21 standard for implementing the algorithm. The proposes mobility-based traffic offload algorithm for vertical handover decisions in scenarios with various traffic types and speeds of the mobile nodes avoids unnecessary vertical handover from WiMAX to WLAN. Furthermore, it shows improvements on vertical handover latency, packet loss and average throughput for mobile VoIP.