In this article, we investigate an artificial traffic model on scale-free
networks. Instead of using the routing strategy of the shortest path, a
generalized routing algorithm is introduced to improve the transportation
throughput, which is measured by the value of the critical point disjoining the
free-flow phase and the congested phase. By using the detrended fluctuation
analysis, we found that the traffic rate fluctuation near the critical point
exhibits the 1/f-type scaling in the power spectrum. The simulation results
agree very well with the empirical data, thus the present model may contribute
to the understanding of the underlying mechanism of network traffics.Comment: 6 pages, 5 figure