A client-based vertical handoff approach for seamless mobility across heterogeneous wireless networks
With the rapid growth of mobile Internet, offering seamless connectivity in different types of wireless networks is an important feature in next generation wireless networks (4G networks). Mobile IP (MIP) is expected to play a key role to handle the movements of mobile nodes (MNs) in 4G networks. However, MIP suffers from long handoff latency since it is designed to support the macromobility of a MN. Therefore, it is necessary to devise a scheme that provides currently deployed networks with backward compatibility and that offers seamless connectivity during MIP handoffs across the heterogeneous wireless networks. In this paper, we propose a client-based vertical handoff system for multi-networks to provide end-users with seamless connectivity across heterogeneous wireless networks. Our proposed system is designed as a common network interface at a client side and provides transparent service to IP/MIP layers regardless of used wireless technologies. With this system, we also present vertical handoff performance over a loosely coupled cdma2000/WLAN experimental test-bed. The experimental results show that our system enables a MN to handoff seamlessly across different types of wireless networks without any modifications to the existing IP/MIP stack and core network. Copyright  2008 John Wiley & Sons, Ltd.
vertical handoff heterogeneous wireless networks 4g networks mobile ip seamless handoff