  Traffic dynamics on single or isolated complex networks has been extensively
studied in the past decade. Recently, several coupled network models have been
developed to describe the interactions between real-world networked systems. In
a system of interconnected networks, the coupling links refer to the physical
links between networks and provide paths for traffic transmission. Thus, the
coupling pattern, i.e., the way coupling links are added, has a profound
influence on the overall traffic performance. In this paper, we employ a
simulated annealing (SA) algorithm to find a near-optimal configuration of the
coupling links, which effectively improves the overall traffic capacity
compared with random, assortative and disassortative couplings. Furthermore, we
investigate the optimal configuration of coupling links given by the SA
algorithm and develop a faster method to select the coupling links.
