The freedom in mobility and flexibility is provided by the ability to achieve wireless entrance anytime, anyplace and anywhere is turn into a common expectation nowadays. While any existing wireless frameworks do not provide the particular solutions for the vertical handoff, the Always Best Connected or back-to-back Vertical Handoff concepts explaining in this book presents a new picture for performing the vertical handoff in various WN. This concept offers a fresh design to check the availability of the network, then it selects the best accessible network for the application layer for delivering network services with no kind of interruption. While our approach can be easily implemented, this approach depends only on available technologies and protocols (AODV and DSR). This book contains all the simulation results which are generated by utilizing Network Simulator. The results of different tested scenarios indicate the efficiency of the implemented approach.