Research On Optimization Strategy Of Coupled Network Information Transmission

Complex network theory is an important tool to study the structure and function of various real networks.Network transmission function is one of its most important functions.Nowadays,with the continuous development of society,economy and technology in the era of big data,the amount of data in the network has increased dramatically.For example,the increase of traffic vehicles in traffic networks,the users and services in communication networks,the electricity consumption in power network and so on.The information in the network is transmitted in the unit of data packet,and when the network traffic capacity cannot meet the growth of packets,network will be congested,even paralyzed.Therefore,how to effectively improve the network traffic capacity to solve the network congestion problem is a hot topic of research.Many networks in reality are coupled together,such as air network and railway network in traffic networks are coupled together to serve the travel,and wired network and wireless network in communication networks are coupled together to complete the information transmission task.Building a coupled network model based on the characteristics of real networks,and then proposing the transmission optimization strategy of coupled networks are the focus of research.Therefore,the traffic dynamic behaviors on the coupled networks are analyzed,the factors affecting the network traffic capacity are explored,and further optimization strategies to mitigate the traffic congestion of coupled networks are proposed.This thesis focuses on the information traffic problem of coupled network from three aspects,routing strategy,network structure and traffic model.1)On the issue of routing strategy,considering that the resources of nodes with high degrees in the low-speed layer may not be well utilized in the network transmission process,an improved traffic-flow assignment routing strategy is proposed.Not only the transmission speed between different layers is considered,but also the difference between different nodes in the same layer is considered.Under the improved traffic-flow assignment routing strategy,the distribution of packet load in the network is more balanced,and the resources at different layers are well utilized.Under the improved traffic-flow assignment routing strategy,the network traffic capacity is improved,and the average length of effective path is shortened.2)On the issue of network structure,aiming at the influence of coupled network structure on traffic capacity,the relationship between different coupled network structure and traffic capacity is studied,and the multilayer network models are constructed by random network and scale-free network models.It is found that the coupled network traffic capacity is greatly affected by the low-speed layer structure.Then on the basis of this conclusion,the structure of low-speed layer is adjusted,and a degree-based link rewiring strategy is proposed.Compared with the random link rewiring strategy,the network traffic capacity is improved under the degree-based link rewiring strategy,and it is verified that the link rewiring strategy can improve the network traffic capacity under different network sizes.3)On the issue of traffic model,according to the information traffic behavior of coupled networks in reality,a new traffic model is proposed.Compared with the previous model,under this traffic model,all nodes in the network have the ability to generate packets,and it takes time to transmit packets between coupled nodes.The new traffic model can better reflect the transmissions of packets in the case that the transmissions between real coupled networks take time.