Research And Simulated Implementation Of Qos Handoff Mechanisms Based On Ga With Abc Supported

The rapid development of Internet and communication technology has brought tremendous changes to the way people work and live. In a larger, faster, more secure, more convenient NGI(Next Generation Internet) that integrates wired and wireless access technologies, enjoying high-quality network service anywhere and at any time has become people's necessary requirement, which indicates that NGI must provide QoS (Quality of Service) guarantee and support ABC(Always Best Connected). Therefore, people can choose the "best" way to access to network and enjoy the service.In this paper, an intelligent handoff mechanism with ABC supported is designed. In order to ensure that users can choose the "best" way to access to network, inaccuracy of network state information, user preference, user utility, service provider utility and fairness of both sides are considered comprehensively. First, the state information of NGI can not be described exactly due to the dynamics and aggregation of network information. So the network model and mathematic model are designed to solve the problem of the inaccuracy of network parameters. Second, when the users access to network, they always hope to acquire the best services with the least cost. However, service providers always pursue the most profits. Therefore, it is necessary to design a "win-win" handoff decision mechanism. In this paper, both of the users'and the service providers'benefits are considered. According to the charge users pay and the QoS requirements users give, the network resources are allocated reasonably. Game theory of micro-economics is used to assure that customers employ the resources rationally and that the utilities of both sides can achieve the state of Nash equilibrium. Besides, two kinds of GA (Genetic Algorithm) are adopted to solve the multi-objective optimization problem, which makes that not only the QoS requirements are satisfied while the users'preference should be considered, but also the utilities of both sides are optimized.To evaluate the performance of the handoff mechanism in this paper, simulation is done in NS2 (Network Simulator 2) environment, and the mechanism is compared with other handoff mechanisms. The simulation results show that the mechanism is feasible and can solve the handoff decision problem with ABC supported in NGI effectively.