| The main characteristics and development trend of the future communicationnetwork will be heterogeneous, complementary, and collaborative convergence among allkinds of communication networks with different technologies. The heterogeneousconverged network is expected to support multi mobility and diverse network services ofend users. While any research works have been done regarding heterogeneous convergednetwork, to support the terminal users independently choose the access network throughIP backbone, there are still many technical issues need to be further studied. The thesisfocuses on the three relevant technology aspects in the area of network access selectionfor the heterogeneous converged network.To support the access selection function in heterogeneous converged multi modeterminal, a design scheme of user oriented visualized operational device at user terminalis proposed, which provides the device platform of terminal function for performing therelated schemes of network access selection. According to the different network servicescharacteristics and application scenarios, terminal users is able to independently choosedifferent access networks through above interactive device platform based on themonitored state information of access networks.The QoS evaluation problem of heterogeneous access network as a basis of accessnetwork selection is studied. The existing evaluation methods of the heterogeneous accessnetwork QoS are analyzed and summarized, a QoS evaluation model based on Sigmoidand SAW is proposed, which focuses on the user actual experience of different networkservice quality and the characteristics of the evaluation model are examined via numericalsimulations.The problem of designing heterogeneous network access selection schemes is alsoconducted, and a game theoretic heterogeneous network access selection scheme isproposed. Different kinds of competitive relations among access networks and users areformulated and analyzed based on game theory, and two game models, i.e., "user versusthe non cooperative game networks"and "user versus cooperative game networks" aremodeled. The Nash equilibrium price strategy and coalition price strategy are formulatedto maximize the network profit for noncooperative networks and cooperative networksand a network access selection algorithm for maximizing user performance cost ratio is proposed to ensure users get maximized network service quality per unit service fee.Finally, the simulation are performed to evaluate and compare the pricing schemes ofaccess networks in different game models, and the performance cost ratio user can obtainin the different game scenarios. The proposed schemes aim to provide a win win solutionwhich can maximize the interests of both access networks and end users in theheterogeneous converged network. |
