Study On Network Selection Algorithm Based On Network Perornace And Service Features In Hetergences Network

The future mobile communication systems will be a complex environment which contains avariety of access networks. There are many distinctions like coverage range, capacity, transmitionrate between the different access networks and they can not take place each other in the short term.So the integration of heterogeneous networks is the basic characteristics and development trend ofthe future mobile communication systems. The heterogeneous and coexistence of networks provideusers the choice to choose the access network from some candidates. The problem of networkselection in heterogeneous network environment is researched in this thesis.Based on the analysis and research of the existing network selection algorithm, aheterogeneous network selection algorithm based on combinational weight which combines thetheory of AHP and entropy is given in this thesis to improve the existing algorithms. First, ahierarchical model of network selection problem is built based on different user preference policiesand different type of services to obtain the subjective weight. Then, the entropy weight is obtainedas the objective weight through the entropy theory. Finally, the subjective and objective weights areintegrated to make judgment that which candidate will be the best access network. The simulationresults show the correctness of the algorithm and its ability to balance the load.The pressure of networks is increasing nowadays in the case of the growing number of mobileusers. This thesis researches the network selection method in multi-user scenario based on thecharacteristic of the dense-user area and presents a network selection program based on serviceaggregation. A new function module named Access Buffering function module is given to avoid thebias of network selection in multi-user scenario. Then, the thesis reorganizes the topology of thegroup of users and polymerizes the services through the technology of Ad-hoc network. Thesimulation results show that the network can contain more users without transforming the exitingnetwork infrastructure.