  This paper introduces the Hub Location Problem under Link Failures, a hub
location problem in which activated inter-hub links may fail with a given
probability. Two different optimization models are studied, which construct hub
backbone networks protected under hub links disruptions by imposing that for
each commodity an additional routing path exists besides its original routing
path. Both models consider the minimization of the set-up costs of the
activated hubs and inter-hub links plus the expected value of the routing costs
of the original and alternative paths. The first model builds explicitly the
alternative routing paths, while the second model guarantees that for each
commodity at least one alternative path exists using a large set of
connectivity constraints, although the alternative paths are not built
explicitly. The results of extensive computational testing allow to analyze the
performance of the two proposed models and to evaluate the extra cost required
to design a robust backbone network under hub links failures. The obtained
results support the validity of the proposal.
