Analysis of Horizontal handover and Vertical handover for Heterogeneous access networks

In this paper, we analyze the horizontal handover and vertical handover for ubiquitous networking. Until now many mobility management mechanisms (especially, handover management aspect) have been developed for horizontal handover. As heterogeneous access network appears in current and future networks and the interworking between heterogeneous access networks is needed, the importance of not only horizontal handover but also vertical handover becomes increasing. For vertical handover, we compare the characteristics of horizontal handover with the characteristics of vertical handover. Then we describe the requirements for vertical handover.