Date Added: Aug 2011
Heterogeneous networks are integrated in fourth generation. To have seamless communication and mobility between these heterogeneous wireless access networks, support of vertical handoff is required. Vertical handover is convergence of heterogeneous networks for e.g.:- handover between WLAN and cellular networks. In this paper, three algorithms on RSS based vertical handoff are discussed. First, algorithm is adaptive lifetime based vertical handoff, which combines RSS and estimated lifetime (expected duration after which the MT will be able to maintain its connection with WLAN) to decide the vertical handover. Second algorithm, is based on dynamic RSS threshold which is more suitable for handover from WLAN to 3G network. Third algorithm is a traveling distance prediction method, which works well for WLAN to cellular networks and vice versa.