Linear programming method of networking design for carrying traffic from endnodes to a core network at least cost

This invention relates to telecommunication networks of the kind that comprise nodes and trunks (or links) for carrying communication traffic among the nodes. More particularly, this invention relates to methods for designing such networks; i.e., for determining the layout of the physical interconnections within the network, and for choosing the trunk types for implementing such interconnections. Still more particularly, this invention relates to optimization methods for achieving such interconnections at least cost. A method is disclosed, for designing an access network that is to carry communication traffic between end nodes and a core network. Information is provided that describes end node locations, the level of demand associated with each end node, available trunk types and their related capacities, and a cost structure. The cost structure includes a fixed overhead cost for each trunk type, and a service charge per unit distance for each trunk type. The provided information is incorporated in a linear program to find an optimal-cost access network. The linear program is solved to obtain a provisional solution that defines the composition and usage of each link of the optimal-cost access network. For each such link, the composition is defined by a fractional level of investment (incurring a like fraction of the corresponding overhead charge) in each pertinent trunk type. The provisional solution is rounded such that each trunk in which there is a fractional investment is either removed, or replaced by a trunk in which there is an integral investment.