Hub location in backbone/tributary network design: a review

A common architecture for a communications network consists of tributary networks, which connect nodes to hubs, and a backbone network, which interconnects the hubs. Often, because of the size of the problem or the nature of the application, the design of the backbone network and the tributary networks are considered independently. However, in many cases, it is desirable or necessary to treat backbone and tributary design as an integrated problem, in which a key decision is the choice of hub locations. We provide a review of earlier algorithmic work on this integrated problem, drawing from the literature on facility location, network design, telecommunications, computer systems and transportation. Certain key issues in modeling hub location problems in the particular context of communications networks are discussed, and possible avenues for future work are proposed.