Network assisted IP mobility support in wireless LANs

In recent years, wide bandwidth and low cost wireless LAN (WLAN) technology has emerged as a competitive choice for high speed wireless Internet access. To support the Internet mobility for the frequently moving mobile nodes in the local WLAN environment, Mobile IP has been found to be inefficient due to its high location update and packet delivery cost. This paper proposes an alternative architecture for network-layer mobility support using dynamic client configuration and transparent proxy mechanism. The attractive feature of our solution is that it requires no change in the legacy network infrastructure. We have implemented a prototype of the proposed architecture, and have taken experimental measurements to evaluate its performance. Experimental results show that the proposed architecture is capable of supporting IP mobility with the handoff delay less than a second. In addition, we have done an analytical study to test the scalability of the proposed architecture. Results show that performance of the architecture is not severely affected by the user mobility and a commonplace router is capable of supporting a considerable number of such users.