الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 103 |  |  |
| | | from | 103 | | |
Abstract
In the near future, every Mobile Node (MN) will be coupled with a location tracking device; this is because of the ••. ttractive location-based services and the continuous reduction of technology prices. Moreover, the growing demand of multimedia and real time applications requires a seamless handoffwithout packet losses.
With such coupling, it seems that the Mobile IP (MIP) Handoff latency can be minimized using the movement information provided by these location tracking devices. Two we\1 known approaches are proposed by IETF (Internet Engineering Task Force) to reduce the MIP Handoff latency. One of them tries to reduce registration and binding update latency through a Hierarchical Mobility Management structure [I] by introducing the concept of Macro and Micro Mobility, while the other tries to minimize the address reconfiguration through fast handoffs [2]. However, neither of them addresses the problem of Handoff Decision time ”when to take the decision” nor provides a clear movement detection mechanism. They depend on either the routers’ (agents’) advertisements or indications from link layer. In both cases layer 3 handoff (MIP Handoff) occurs after layer 2 handoff resulting
on performance degradation and packet losses.
In this thesis, a novel handoff decision strategy is proposed. The proposed handoff procedure utilizes the movement information provided by the location tracking devices and information about IP ce\1s topology to predetermine the next Foreign Agent (FA) and the handoff decision time, ”where and when to handorr’, The proposed handon’ procedure complements the mechanism of Fast l-IandolT described in [2] and Simultaneous Binding described in [3] with the movement tracking of MNs to provide a seamless handolT and decouples layer 3 handoff
from layer 2 handoff.
Two approaches are presented to develop the proposed hand off procedure. The first approach is distributed and mopile-contro\1ed (network-assisted) in which the FA provides the MN with the neighbor F As information and the MN is responsible of taking the handoff decision. On the other hand, the second approach is centralized and network-contro\1ed (mobile¬assisted) in which the MN continuously provides its current FA with its movement information and the FA takes the decision of the handoff.
The proposed handoff procedure is evaluated through simulation and compared to current handoff methods. Moreover, the overhead of the proposed handoff procedure is discussed through a cost analysis. The simulation results show that the proposed handoff procedure outperforms other handoff procedures with a little incrcase in signaling overhead. Moreover, the proposed handoff procedure gives layer 3 h’lI1dolT latency similar to that of layer 2
handoff.