Mobility management in the wireless Internet

In this thesis, we present technologies for candidate access router discovery, fast handoff, load balancing and survivable hierarchical mobility management in the wireless Internet. Different from the cellular networks, mobile nodes have primary control of handoff or network access point selection in the wireless Internet. Therefore, it is essential to provide mobile nodes with information necessary for intelligent and efficient handoff control, for which the candidate access router protocol is a solution. We present a secure candidate access router protocol by which each access router can discover in a dynamic and distributed fashion its neighboring access routers who serve the areas overlapping the local cell and provide collected information from the neighboring access routers to mobile nodes.; Fast handoff is important for no disruption of interactive real-time media application such as VoIP and video conferencing. We present two fast handoff mechanisms, NeighborCasting that utilizes only EP level information and Integrated Proactive Handoff that is based on integrated control of the link layer handoff and IP layer handoff. The latter technique enables minimization of even link layer handoff and thus seamless audio traffic during handoff. We also present an algorithm to estimate the available (or free) capacity of a wireless link in wireless packet networks and a distributed load balancing mechanism that is based on the metric, free capacity. Included are investigation on handoff cost and methods to assure the handoff decision does not result in excessively frequent preemptive handoff for load balancing.; The last section of the thesis is devoted to survivable hierarchical mobility management which aims to address the reliability issues of many existing approaches for hierarchical approaches. We show that anycast-based clustering of mobility agents makes it very simple to recover or maintain connectivity of mobile nodes in the case of a mobility agent failure in the hierarchical mobility management. Furthermore, we investigate the anycast concept and present a couple of anycast-routing mechanism, including the one that we designed. Also we introduce Application Load Sensitive Anycast Routing which enables more effective load balancing by reflecting the application load status into the routing decision of anycast.