In future heterogeneous 4G network there may be
several available networks at the same time and location. A
mobile terminal needs to switch from one wireless system to
another. During this process, how to execute the vertical handoff
at the right time and how to satisfy all the applications working
on mobile terminal are still exciting research fields. Based on
current researches of vertical handoff decision strategy, we
develop an enhanced scheme with cost function that gives a
relative overall consideration on the different factors that affect
the handoff quality, of which we especially focus on the effect of
application requirements. On weighting of the different factors,
the Analytic Hierarchy Process algorithm is adopted. Our
research shows that this enhanced application-driven vertical
handoff decision scheme is efficient and reliable during the whole
handoff process