On the mobility and QoS support in wireless Internet.

摘要

As the Internet is gaining more and more popularity and wireless networks are evolving towards the third and fourth generations (3G/4G), we are witnessing the convergence of wireless networks and the Internet. Wireless Internet users require not only seamless mobility support but also certain level of QoS assurance. However, uncertainty in the availability of resources and services mainly due to user mobility as well as error-prone and bandwidth-limited wireless communication links make the QoS provisioning in mobile Internet more challenging than that in the wired Internet.; This dissertation proposes novel architectures and protocols for the mobility and QoS support in wireless IP networks. Firstly, we propose the Intra-Domain QoS Architecture (IQoSA) for integrated QoS and mobility support for fast moving mobile users within an IP-based wireless access domain. This framework is based on the Differentiated Services (Diffserv) model with a centralized Bandwidth Broker (BB) performing admission control and resource provisioning for different traffic classes. The IQoSA architecture is derived by enhancing the Intra-Domain Mobility Management Protocol (IDMP) with the QoS functions, which is used for QoS signaling as well as mobility signaling. Analytical and experimental results show that signaling traffic in IQoSA results in less overhead compared to alternative solutions for fast and active intra-domain mobility. Moreover, the QoS processing overhead does not result in the increase of handoff latency. Aggregate resource reservation and failure recovery schemes in IQoSA have also been proposed for achieving better system scalability and resiliency. In addition, mobility management solutions have been proposed for mobile nodes that change points of attachment frequently within a local domain and also roam between networks using different wireless access technologies. For the former problem dealing with intea-domain mobility, we propose a network architecture to provide the IP mobility support in wireless local area networks (WLANs) while requiring minimal changes to the underlying network infrastructure as well as the mobile nodes. For the latter problem dealing with inter-system or vertical mobility, a mobile agent-assisted mobility scheme is proposed to address the needs of a mobile user for seamless roaming in heterogeneous wireless overlay networks.