  In a topological structure affected by geographical constraints on liking,
the connectivity is weakened by constructing local stubs with small cycles, a
something of randomness to bridge them is crucial for the robust network
design. In this paper, we numerically investigate the effects of adding
shortcuts on the robustness in geographical scale-free network models under a
similar degree distribution to the original one. We show that a small fraction
of shortcuts is highly contribute to improve the tolerance of connectivity
especially for the intentional attacks on hubs. The improvement is equivalent
to the effect by fully rewirings without geographical constraints on linking.
Even in the realistic Internet topologies, these effects are virtually
examined.
