Research On Network Decision Algorithm In Heterogeneous Wireless Networks

An important feature of the current wireless network scenario is that multiple wireless access technologies exist in the same area and mutually overlap to form a heterogeneous wireless network.Due to the difference between different wireless access technologies,the terminal needs to consider the influence of multiple factors when selecting a network and cannot be selected solely by judging the signal strength between networks.One of the hot research in the heterogeneous wireless networks is the network selection algorithm,a reasonable choice of network needs to consider user preferences,terminal performance,network characteristics and other factors.Based on the classical multi-attribute network selection algorithm,this thesis applies the theory of game theory,coordination and group decision-making to the field of heterogeneous wireless network selection and proposes several heterogeneous wireless network selection algorithms suitable for new communication scenarios.Nowadays,there are many types of communication services,and it is more and more common for a terminal to have multiple types of service communicating at the same time.Based on this,this thesis presents two algorithms to solve such problems,one is network selection algorithm based on group decision making for heterogeneous wireless networks.The algorithm considers each service from the terminal as a decision-maker,and obtains the weight vector of all network attributes for each service by the analytic hierarchy process,then uses the group decision making to synthesize these weight vectors.At the same time,the utility function is used to normalize the network attributes.At last,the network selection is made according to the synthesized weight vector and attribute utility.The other is a network selection algorithm based on synergetic for heterogeneous wireless network.The algorithm considers the terminal selection network as a systematic problem.The optional network is a composite system.Each kind of service running on the terminal is a subsystem.The entropy of the composite system is obtained according to the concept of entropy.The entropy reflects the degree of coordination among the subsystems,and thus the overall performance of the network.The simulation results show that the proposed algorithms are far superior to the TOPSIS algorithm in satisfying the multi-service QoS requirements of the terminal.Considering single access network selection algorithm to utilize network resources inefficiently,a multi-access network selection algorithm based on evolutionary game is proposed for heterogeneous wireless networks in this thesis.The algorithm considers any non-empty subset of heterogeneous wireless networks as a selection scheme and network performance is analyzed from the perspective of throughput and power consumption.The dynamic selection of the network is regarded as an evolutionary game and the Jacobi matrix local stability analysis method is used to discuss the system equilibrium.Simulation results show that compared with the single access algorithm,the multi-access network selection algorithm based on evolutionary game can provide users with greater throughput and the corresponding power consumption is relatively small,so this algorithm can make more efficient use of network resources...