Efficient Micro-Mobility using Intra-domain Multicast-based Mechanisms (M&M)

One of the most important metrics in the design of IP mobility protocols is the handover performance. The current Mobile IP (MIP) standard has been shown to exhibit poor handover performance. Most other work attempts to modify MIP to slightly improve its efficiency, while others propose complex techniques to replace MIP. Rather than taking these approaches, we instead propose a new architecture for providing efficient and smooth handover, while being able to co-exist and inter-operate with other technologies. Specifically, we propose an intra-domain multicast-based mobility architecture, where a visiting mobile is assigned a multicast address to use while moving within a domain. Efficient handover is achieved using standard multicast join/prune mechanisms. Two approaches are proposed and contrasted. The first introduces the concept proxy-based mobility, while the other uses algorithmic mapping to obtain the multicast address of visiting mobiles. We show that the algorithmic mapping approach has several advantages over the proxy approach, and provide mechanisms to support it. Network simulation (using NS-2) is used to evaluate our scheme and compare it to other routing-based micro-mobility schemes - CIP and HAWAII. The proactive handover results show that both M&M and CIP shows low handoff delay and packet reordering depth as compared to HAWAII. The reason for M&M's comparable performance with CIP is that both use bi-cast in proactive handover. The M&M, however, handles multiple border routers in a domain, where CIP fails. We also provide a handover algorithm leveraging the proactive path setup capability of M&M, which is expected to outperform CIP in case of reactive handover.Comment: 12 pages, 11 figure

An algorithm for join/prune mechanisms for improving handoff using mobility prediction in wireless networks

In this paper, we provide a detailed description of an algorithm that implements join and prune mechanisms, which will help to build an optimal multicast tree with QoS requirements during handoff. An analysis is presented to show how mobility prediction can help in the selection of potential access routers (AR) with QoS requirements that affect multicast group size and bandwidth cost in the multicast tree. The proposed technique tries to minimise the number of multicast tree join and prune operations. We have examined the performance of this algorithm using simulations in various environments and obtained good performance results. Our results show that the expected multicast group increases linearly with the increase in the number of selected destination access routers (AR) for multicast during handoff. We observe that the expected number of joins and prunes from the multicast tree increases with group size. Thus, for an increased number of destinations, the estimated cost of the multicast tree in a cellular network also increases

A Framework of Cooperating Agents Hierarchies for Local-Area Mobility Support

Host mobility creates a routing problem in the Internet, where an IP address reflects the network\u27s point of attachment. Mobile IP, relying on a mapping between a home address and a care-of address, and a home registration process, is widely accepted as a solution for the host mobility problem in wide-area mobility scenarios. However, its home registration requirement, upon each change of point of attachment, makes it unsuitable to handle local-area mobility, resulting in large handoff latencies, increased packet loss, and disrupted services. In this dissertation, we introduce a local-area mobility support framework for IPv4 based on the deployment of multiple cooperating mobility agents hierarchies in the foreign domain. First, we introduce a hierarchy model offering a backward compatible mode to service legacy mobile hosts, unaware of local-area mobility extensions. Second, for intra-hierarchy handoffs, we identify several design deficiencies within the current Mobile IP hierarchy extension proposal, and present an enhanced regional registration framework for local handoffs that encompasses a replay protection identification value dissemination mechanism. In addition, we present two novel registration frameworks for home registrations involving local handoffs, in which we identify the dual nature of such registrations, and attempt to emphasize the local handoff aspect. One technique, maintains tunneling of data packets to the MH (Mobile Host) through an old path until a home registration reply is received to set up the new path. In contrast, the other technique adopts a more proactive bold approach in switching immediately to the new path resulting in a reduction of the handoff latency. Third, for inter-hierarchy handoffs, we present a scalable, configurable, and cooperation based framework between mobility agents hierarchies to reduce the handoffs latencies. An attempt is made to exploit the expected network proximity between hierarchies within the foreign domain, and maintain a mobile host\u27s home-registered care-of address unchanged while within the same foreign domain. In addition, the involved registration signaling design requires a reduced number of security associations between mobility agents belonging to different hierarchies, and copes with the fact that the mobile host\u27s home-registered care-of address might not be reachable