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Abstract
Handover management is one of the major problems for the global wireless services, it leads to cell loss and cell delay variation which are two of the major causes of degradation in quality of service in mobile IP. In this thesis we analyze IPv6 Handover over wireless LAN. WLAN is receiving a lot of attention because of its high data rate and low cost. Mobile IPv6 is designed to manage mobile stations movements between wireless IPv6 networks nevertheless, the active communication of a mobile station is interrupted until the Handover completes. Therefore, several extensions to mobile IPv6 have been proposed. We describe two of them: hierarchical mobile IPv6 which manages local movements into a domain, and Fast Handover, which allows the use of layer 2 triggers to anticipate the Handover. It presents two extensions, namely Anticipated handover, and Tunnel-based handover. We expose the specific Handover algorithms proposed by all of these methods. The performance of the network during Handover for both extensions of the mobile IPv6 must be augmented with mobility management capabilities. One of the important components of mobility management is the ability of the network to seamlessly re-route existing connections to different parts of the network. To date, a number of schemes have been proposed for broadband wireless networks. These schemes can potentially be used in WLAN networks for handover re-routing techniques such as, connection restablishment scheme in the mobile IPv6 technique, path extension, Anchore re-routing, and Dynamic re-routing schemes in the hierarchical mobile IPv6 technique and multicast, Static virtual connection tree, and Dynamic virtual connection tree re-routing schemes in the anticipated handover technique.
In this thesis, we compare the performance of these schemes in terms of their important Quality of Service (QoS) parameters, such as complexity, throughput, utilization, Handover latency, communication disruption period and buffer and bandwidth requirements. We analyzed the issue of overhead in fast handover. Based on our analysis, we concluded that the total amount of overhead is largely dependent on when the L2 trigger is notified to layer 3 (L3), therefore, we studied the optimal point in the time for the L2 trigger to occur, in order to minimize the total overhead.