| With the emergence of modern communication technologies such as the Internet and the World Wide Web,it has greatly facilitated the communication between people in different regions.It has been in an era of large traffic and big data for current society,and with the increase of the number of internet users is increasing,the data in the network is increasing exponentially.While enjoying the convenience brought by information technology,people are also suffering from the trouble brought by communication congestion.Because of the information surge or natural disasters in some important holidays,the destruction of communication lines could collapse,which bring great loss to economies and lives of people.Therefore,how to ensure the stable and efficient transmission of information has become one of the key research topics for researchers in the field of complex networks.In this thesis,we improve the routing strategy to enhance the transmission capacity of the network based on the model of BA scale-free network.The main work is as follows:1)The optimized routing strategy of the waiting time of information packets.In the process of packets transferring from the current node to the next node,the degree of each neighboring node and the number of queued packets are considered.If the length of queued packets at the neighboring node is greater than the capacity of packet processing(set packet processing capacity of the node=the degree value of the node),the packets should be avoided from being transferred to such nodes.The node with the maximum degree value of the neighboring nodes should be selected,whose capacity of processing packets is greater than its number of queued packets.This routing strategy can effectively avoid the network congestion caused by the accumulation of information packets in the nodes with large degree.It can be obtained that compared with the routing strategy based on the information of degree the routing strategy of the waiting time of information packets has better network transmission performance.When the produce rate of network packet is larger,for the routing strategy of the waiting time of information packets the average time of information packets reaching to target nodes is shorter than that of the routing strategy based on the information of degree.2)The routing strategy of information packets combined with betweenness.In real network,the importance of nodes is different generally,and the betweenness of node is a very important index to identify nodes.Therefore,in this paper we established the routing strategy including both the betweenness of nodes and the number of queued packets.Using simulation experiment for BA scale-free network,it is found that under certain parameter the routing strategy combining with betweeness can further optimize the routing efficiency of packets after taking into account the betweenness and the number of queued packets of nodes.When the parameterα=-0.5,the transmission efficiency of packets reaches the highest,and the transmission capacity of the network is further improved compared with the routing strategy based on the waiting time of information packets.3)A local routing strategy based on the information of target node is established.In the routing process of information packets from the source node to the target node,some neighboring nodes,which can be regarded as the partial information of the target node,will be searched in each time step.It can be get that the generation rate of critical packets R_c can be greatly advanced on the basis of the local information of target nodes.The number of packets,which do not reach its target node when the program is over,will be reduced.The average time of packets arriving at target nodes is also greatly shortened in the routing strategy based on the information of target node.In addition,the more information about neighboring nodes of the target node is known,the larger the transmission capacity of the network is. |
