QoS Provisioning in Seamless Vertical Handover of WIMAX/WLAN Overlay Network

The integration of WiMAX and WLAN has been seen as a promising approach towards fourth generation (4G). Vertical handoff plays important role while integration of WiMAX and WLAN heterogeneous overlay systems. Vertical handoff is preformed on the basis of Quality of Service (QoS) metrics of the two heterogeneous networks. A Seamless handoff scheme is based on the tightly coupled architecture so that undesirable signaling cost induced by the mobile Internet protocol can be avoided with aim to provide always best QoS for the users (mobile and fixed). By using the ad-hoc on demand multipath distance vector protocol a simple evaluation algorithm is used to measure the QoS metrics such as available bandwidth and packet delay of both mobile and fixed users. The proposed scheme can keep the users always being best connected. Keywords— QoS, Seamless Vertical handover, AOMDV