A network layer seamless handover scheme based on Xcast for wireless LANs

In order to apply time-critical applications to wireless LANs, a seamless handover scheme is needed. Therefore, we present a novel micro-mobility scheme based on explicit multicast (Xcast). In our proposal, mobile traffic of its forward direction is delivered to the potential access routers (AR) of a mobile node (MN) by Xcast routing during handover. Since, for IEEE 802.11 wireless LAN, it is difficult to know the potential ARs of a mobile node, a new trigger, called the candidate AR trigger (CAT), is introduced to get this information from the link layer. The handover mechanism of our proposed scheme is depicted in detail and the merits of this scheme are also discussed. Finally, by using a combination of performance evaluation and simulation, we argue that our architecture is capable of providing seamless handover while introducing limited network bandwidth overhead.