Research On Optimized Mechanism Of Secure And Fast Vertical Handoff In Heterogeneous Wireless Networks

Secure and seamless vertical handoff of mobile node is the most urgent problem in heterogeneous wireless integrated networks. Secure and seamless should not only ensure the security, but also consider the performance to satisfy the QoS of real-time network services. The current state of the art for handoff control does not have specific solution from the angle of mutual effect between secure mechanism and mobility protocol. Therefore, this dissertation carries out a detailed research on the control of secure and fast vertical handoff. Two optimized mechanisms of secure and fast vertical handoff are proposed, which take account of the trade-off between security and efficiency of handoff. The main contents are outlined as follows:1. The vertical handoff control protocols and handoff authentication mechanisms are studied. Towards the core network of heterogeneous wireless integrated networks based on full-IP architecture, this thesis stress analyzes secure vertical handoff control with MIPv6-AAA. After a detailed discussion about the performance of handoff, the detailed factors through which handoff authentication impacts on handoff performance is definitely presented.2. To resolve the problem that executing all operations in sequence would severely affect the handoff efficiency, a concurrently executing optimized mechanism of secure and fast vertical handoff based-FMIPv6(CE-FMIPv6) is proposed. The mechanism uses FMIPv6 to support vertical handoff and completes the handoff authentication by improved wireless shared key exchanging protocol (W-SKE) in the network layer. The mechanism adequately uses the bidirectional tunnel established by FMIPv6, and concurrently executes the handoff of layer 2, authentication and binding update. The efficiency of CE-FMIPv6 is studied through numerical analysis and NS-2 simulation, and the result indicates that handoff latency of CE-FMIPv6 is reduced obviously compared with the executing mechanism in sequence.3. To resolve the problem that the authentication latency increases quickly as the change of distance between home network and foreign network with the home network centralized control, an optimized mechanism of secure and fast vertical handoff is proposed, which is based on secure context transfer. The mechanism establishes the secure transmission channel through signature certification and asymmetric encryption, and then distributed controls the handoff authentication with context transfer. The analysis of the mechanism shows that it can obviously improve the handoff efficiency and realize secure and fast vertical handoff, while mobile node executes vertical handoff frequently away from home network.