Multiple traffic states and Braess' paradox in dynamical networks with limited buffer size

Traffic dynamics has always been a research hotspot of complex networks. In this letter, dynamical networks in which the nodes are moving with limited buffer size are studied. We propose an adaptive routing strategy where Euclidean distance and node load are combined by a tunable parameter. The packet loss and traffic congestion can be observed in our model due to limited buffer size. Traffic congestion will occur unless the tunable parameter is in a critical interval. We mainly focus on the impact of the buffer size on traffic congestion and obtain four different traffic states: partial-, short-, no- and long-congestion state. Moreover, a phenomenon similar to the Braess' paradox can be observed in our model. We also find that the higher the node speed, the worse the traffic capacity