NACS: non-overlapping AP´s caching scheme to reduce handoff in 802.11 wireless LAN

With the escalation of the IEEE 802.11 based wireless networks, voice over IP and analogous applications are also used over wireless networks. Recently, the wireless LAN systems are spaciously deployed for public Internet services. In public wireless LAN systems, reliable user authentication and mobility support are indispensable issues. When a mobile device budges out the range of one access point (AP) and endeavor to connect to new AP, it performs handoff. Contemporarily, PNC and SNC were proposed to propagate the MN context to the entire neighboring AP´s on the wireless network with the help of neighbor graph. In this paper, we proposed a non-overlapping AP´s caching scheme (NACS), which propagates the mobile node context to those AP´s which do not overlap with the current AP. To capture the topology of non-overlapping AP´s in the wireless network, non-overlapping graph (NOG) is generated at each AP. Simulation results shows that NACS reduces the signaling cost of propagating the MN context to the neighbor AP´s in the wireless network.