Locating interactive hub facilities

We examine the problem of simultaneous determination of facility location and flow routing in the context of hub location in private-line networks. The flows in this case are the number of channels of communication demanded between the user locations, and the facilities location aspect is due to the need to analyze the location of hubs to service the need between the user locations. Hubs are special points in the network containing switching equipment which serve to connect the network links. We address questions about the topology of the network using hubs: where should the hubs be located, how should the node-hub assignments be made, which network links should be provided, and what are the capacities of these links. Three special situations of the problem are examined in detail providing mathematical formulations, complexity arguments, analysis of special characteristics and special cases of the situations, solution strategies, bounding strategies, and computational experience with randomly generated problems. A description of interesting extensions to this research are suggested.