To allow a seamless integration between wireless LANs and Wireless WANs, we developed a full stack adaptation model and a simple subnet architecture that superimposes Mobile-IP on cellular-type wireless LANs. The idea is to use Mobile IP as an integrative layer atop different LAN/WAN networks. While Mobile-IP is widely used in wireless WANs, it is not known how well it performs under a wireless LAN environment, against native MAC-level handoff. Through experimentation using 802.11 W-LAN, we found that under practical values of handoff frequencies, the performance of Mobile IP based W-LAN handoff is almost identical to the performance of W-LAN handoff. Further performance studies show the suitability of Mobile-IP as an integrative layer in this architecture.