Research On Self-organization Criticality Of Intelligent Optical Networks

In recent years,with the wide used of ASON,OTN and other intelligent equipment,the intelligence of optical network has improved gradually and increasing in nodes and capacity lead to the increased complexity in physical and logical topology.The intelligent optical networks with dynamic scheduling and self-healing protection in long-term operation and maintenance will bring on the mismatch between topology and bandwidth allocation,unbalance capacity allocation between links,cyber capacity will not meet the use of users.The interaction between the increased users demand and spanning of networks scale will induce the self-organized critical state in the optical networks.Under this circumstance,the system has strong possibility to be collapsed part or whole area caused by jamming.Therefore,it is necessary to avoid optical networks reach a critical state.This paper based on the quality evaluation of IP client layer,aiming at automatic routing protection for intelligent optical networks,conducting in-depth research in the self-organized critical phenomenon of optical networks.Principal works and innovation results are listed below:(1)Researching self-organized critical theory,analyzing the complexity of intelligence optical networks,which indicates that dissipative structure exists in optical networks.(2)Modelling on the real optical network topology,calculating essential feature parameters based on the complex networks.It indicates that the evolution of this optical network has following character,first,comparing the average path length and clustering coefficient with the same scale random network can find that this real network has larger average path length and much larger clustering coefficient than the random network,it matches a small-world network nature.Its node degree distribution is consistent with power-law distribution,this optical networks with scale-free characteristics.(3)Following the evolution rule of sand pile model,quality of IP client layer used as collapse assess condition,building an intelligent optical network self-organize critical model.By researching dynamic evaluation of the intelligent optical network,the model parameters are designed and optimized,it designed algorithm by this model to find out the critical load point of this whole network.(4)Simulating on the self-organized critical model of a real network.It shows that,firstly,self-organized critical state existing in intelligent optical networks,and it highly has malfunction problem,secondly,calculating the load critical value of this optical network,and last,analyzing the relationship between critical load and the average of betweenness among nodes.In this experiment,when the load reaches 71%,networkcomes into critical state,if load switch occurs in other nodes,the network will be collapsed because of self-preservation recovery function,thus,it reduces the support capability of optical network.By following analyzing the relationship between critical load and betweenness among nodes,it find that when arriving rate of data pack is constant,critical load is lower in the network which has more complicated link and the average of betweenness is higher,while the average of betweenness is constant,a higher rate of data pack arrive means lower critical load value.