A New Seamless Handoff Mechanism for Wired and Wireless Coexistence Networks

This paper deals with design and implementation of seamless handoff mechanism between wired and wireless network adapters for a system with both network adapters. A unique virtual adapter is developed between different adapters and then an IP address is assigned to the virtual adapter. As a general rule, when both network adapters are available, the wired adapter is preferred due to its faster transmission speed than the wireless adapter. When wired communication via the wired adapter gets disconnected while in service, the disconnection of wired adapter is automatically detected and then wireless handoff occurs by mapping information on the wireless adapter to the virtual adapter. According to the proposed handoff mechanism, the session can be continued seamlessly even when handoff between wired and wireless network adapters occurs at lower level in a network application where both IP address and port number are used to maintain session. To evaluate the proposed handoff mechanism, actual experiments are performed for various internet applications such as FTP, HTTP, Telnet, and then their results are discussed.