The Application Of Fuzzy Discrete Event Systems In Vertical Handover In Heterogeneous Networks

As the development and progress in information and communication technology and increasing human demands, the next-generation communications networks are no longer limited to cellular mobile communication network, it will be a integration based on a variety of different access technologies, named heterogeneous networks. Vertical handover has been a key technology in handover performance to support continuity in the conversation of mobile users across heterogeneous network. These users are roaming among heterogeneous network wirelessly. Because of the occurrence of discrete vertical handover, with fuzzy parameters, we introduced a fuzzy discrete event systems (FDES) in vertical handover on the heterogeneous networkIn this paper, we have summarized the latest researches and development trends of the vertical handover technology in heterogeneous network, mainly focusing on the issues of vertical handover decision-making, including the fuzzy DES (FDES) modeling, multi-attribute decision analysis. The major contributions of this dissertation are as following:(1) Introduced the concept and modeling methods of FDES, F. Lin’s research results on the FDES fuzzy modeling and automation. Studied a method of the state transferring, provided a practical approach about structure FDES fuzzy state transition matrix.(2)Introduced the concept of heterogeneous network and the handover-related knowledge, the future development direction of communication technologies.Detailed analyzed the main factors which affect vertical handover in the heterogeneous network, and a variety decision-making of vertical handover in heterogeneous network, to choose a better way to model the system.(3)Modeling with fuzzy DES (FDES) method for vertical handover in heterogeneous network, which is a method that the fuzzy states are changed by the event-driven, the effective combination networks which are before and after used in vertical handover to deal with the edge and non-linear problems of vertical handover and to find the better solutions.(4) We will model with fuzzy DES (FDES), compute network efficiency function in a state of a certain moment by the state vector and vector of the attributes which affect vertical handover. Then the system gets roughly the relative size of the QoS, at last, the fuzzy rules are applied for a heterogeneous network environment according to the actual situation. Following the rules, combined with the value of every reference attributes, it will make the vertical handover decision-making in heterogeneous networks.(5)Applied a theory that Vertical handover in heterogeneous network is modeled by fuzzy DES (FDES) to Vehicle Area Network (VAN) which is a specific environment of B3G/4G in the final chapter. Verification the feasibility and superiority in FDES applying to further heterogeneous network switch vertical decision-making.(?)(Telecommunication and Information system)Supervised by(?)...