title: Optimal structure of complex networks for minimizing traffic congestion.
abstract: To design complex networks to minimize traffic congestion, it is necessary to understand how traffic flow depends on network structure. We study data packet flow on complex networks, where the packet delivery capacity of each node is not fixed. The optimal configuration of capacities to minimize traffic congestion is derived and the critical packet generating rate is determined, below which the network is at a free flow state but above which congestion occurs. Our analysis reveals a direct relation between network topology and traffic flow. Optimal network structure, free of traffic congestion, should have two features: uniform distribution of load over all nodes and small network diameter. This finding is confirmed by numerical simulations. Our analysis also makes it possible to theoretically compare the congestion conditions for different types of complex networks. In particular, we find that network with low critical generating rate is more susceptible to congestion. The comparison has been made on the following complex-network topologies: random, scale-free, and regular.
authors.affiliation: Institute of Mathematics and Computer Science, University of São Paulo, São Carlos, SP, 13560-970, Brazil.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Thiago Henrique
authors.initials: TH
authors.lastname: Cupertino
authors.forename: Kwangho
authors.initials: K
authors.lastname: Park
authors.forename: Ying-Cheng
authors.initials: YC
authors.lastname: Lai
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Jin
mesh_terms: D001334:Automobile Driving; D003195:Computer Communication Networks; D003198:Computer Simulation; D004560:Electricity; D006801:Humans; D008433:Mathematics; D015233:Models, Statistical; D008962:Models, Theoretical; D014186:Transportation; D014505:Urban Population