Traffic properties for stochastic routings on scale-free networks
For realistic scale-free networks, we investigate the traffic properties of stochastic routing inspired by a zero-range process known in statistical physics. By parameters α and δ, this model controls degree-dependent hopping of packets and forwarding of packets with higher performance at more busy nodes. Through a theoretical analysis and numerical simulations, we derive the condition for the concentration of packets at a few hubs. In particular, we show that the optimal α and δ are involved in the trade-off between a detour path for α 0; In the low-performance regime at a small δ, the wandering path for α 0 and α < 0 is small, neither the wandering long path with short wait trapped at nodes (α = -1), nor the short hopping path with long wait trapped at hubs (α = 1) is advisable. A uniformly random walk (α = 0) yields slightly better performance. We also discuss the congestion phenomena in a more complicated situation with packet generation at each time step.