A dual algorithm for the uncapacitated hub location problem

Hubs are frequently used in telecommunications and transportation systems as intermediate switching points for traffic. Various model formulations, based on different assumptions and different cost structures, have been proposed for the problem of choosing an optimal set of hubs. The authors describe an algorithm, based on dual ascent and dual adjustment techniques within a branch-and-bound scheme, for one of these models, the uncapacitated hub location problem (UHLP). The dual-ascent technique for UHLP involves the novel feature of using the solution to a transportation problem to determine feasible dual values. Some computational results are described.