Research And Implementation Of QoS Guarantee Mechanism In Mobile IP Networks

With the development of mobile computing technology and increase in diverse requirement of mobile services, end users expect that they can not only access the Internet at anytime in anyplace, but also enjoy the same Quality of Service(QoS) as users of fixed networks. In mobile IP networks, it's difficult to provide QoS because of mobile node's frequent handoffs between different subnets and the unsteadiness of wireless links. Therefore, it is of great significance to study the QoS guarantee mechanism in mobile IP networks. Mobile IPv6 will play a key role in Next Generation Internet, and the research of mechanisms to solve QoS problems in mobile IPv6 environment is the main content of this thesis.Mobile IP can only provide persistent communication for mobile terminals, but it is lack of QoS guarantee support. Nowadays QoS guarantee mechanisms used in fixed networks don't support mobility, therefore they can not applied to mobile networks. In order to support QoS guarantee in mobile IP networks, a DiffServ based scheme is presented in this thesis by analyzing the factors that influence QoS and the related research status of QoS guarantee. Also, methods to provide QoS guarantee in different communication modes are analyzed.Currently, many QoS guarantee mechanisms use the strategy of reserving resource in advance, which can guarantee QoS during mobile node's handoff process, but these mechanisms cause a heavy waste of resource. In order to solve this problem, this thesis presents a historical handoff probability-based resource reservation mechanism. This mechanism sets up a movement model of mobile nodes and reserves resource in advance for the subnet that has the biggish handoff probability. This mechanism can not only provide stable QoS guarantee for mobile node, but also save the valuable wireless network resource and reduce the blocking probability of resource reservation. Finally, we analyze the performance of this mechanism by simulating mobile nodes' handoff in mobile IP networks and validate the superiority of this mechanism.Firstly the thesis introduces the background of the project and related technology briefly, focusing on the research status of QoS guarantee mechanism. Secondly, a scheme to guarantee QoS in mobile IP networks is presented and methods to provide QoS guarantee in different communication modes in DiffServ mobile IP networks are analyzed. Aimed at solving the related problems of present resource reservation mechanism, a historical handoff probability-based resource reservation mechanism is proposed, and the simulation and analysis of this new mechanism are carried out. Then the thesis introduces CNGI QoS management system and mobile IP services management subsystem, describes deployment procedure of mobile IPv6 test bed on which validation on the mobile IP services management subsystem is carried out. Finally, the major work of this thesis is summarized, and the existent insufficiencies and future improvements are pointed out.