Design And Simulated Implementation Of ABC Supported Handoff Decision Mechanisms

With the rapid development of Internet and its in-depth application, people's communication needs growing fast. The ultimate goal of personal communication is that any person at any time, any place can in any way to achieve any kind of communication business. Therefore, supporting ABC(Always Best Connected) and providing QoS(Quality of Service) guarantees become the essential ability of NGI(Next Generation Internet). Based on this background, this thesis designs and simulates the handoff decision mechanisms with ABC supported in NGI.In order to support ABC better, uncertainty of network information, users'QoS requirements, users'preference, charges the users are willing to pay and network providers' utility are all considered in the handoff decision mechanisms of this thesis. To the uncertainty of network information, the state of networks and mobile terminals are considered adequately to design the network model, and fuzzy mathematical knowledge is applied to design the mathematic model. In order to ensure the reasonability of QoS parameters'weights which are set by users according to different applications, analytic compatible matrix method is introduced to compute QoS parameters'weights. Game theory and Nash equilibrium of micro-economics are introduced to consider the benefits of both the network providers and end-users to guarantee the fairness of handoff decision. Users'QoS requirements and preference are considered comprehensively; meanwhile, the benefits of users and network providers are met fully and can achieve all-win. The ABC supported QoS handoff decision mechanisms designed in this thesis are based on five swarm intelligence algorithms, namely, multi-objective genetic algorithm based on elitist selection and individual migration, double bee population evolutionary genetic algorithm, particle swarm optimization based on adaptive diffusion and hybrid mutation, fast continuous ant colony optimization algorithm and an evolutionary algorithm based on cloud model to find the optimal handoff decision for end-users.In order to verify the feasibility and effectiveness of the handoff decision mechanisms, a network simulation environment is built based on NS2(Network Simulator 2), and performance evaluation is done. The simulation results show that the handoff decision mechanisms designed in this thesis can not only satisfy the users'QoS requirements and preference, but also make the benefits of users and network providers largest. Therefore, the mechanisms can solve the handoff decision problem with ABC supported in NGI effectively.