Application signal threshold adaptation for vertical handoff in heterogeneous wireless networks

In heterogeneous wireless systems, the seamless and efficient handoff between different access technologies (vertical handoff) is essential and remains a challenging problem. The co-existence of access technologies with largely different characteristics results in handoff asymmetry that differs from the traditional intra-network handoff problem. In the case where one network is preferred, the vertical handoff decision should be carefully executed, based on the wireless channel state, network layer characteristics, as well as application requirements. In this paper, we present an adaptive preferred-network lifetime-based handoff strategy, and investigate the effect of an application-based signal strength threshold on the signalling load, available bandwidth, and packet delay. We propose an analytical framework to evaluate the performance of the converged system. We show how the proposed analytical model can be used to provide guidelines for the optimization of vertical handoff in the next generation integrated wireless networks.